Ship third-party license texts in plugin ZIPs (#345)

The drawio, excalidraw, and mermaid plugin packages redistribute
third-party material (the draw.io webapp, the Excalidraw editor and its
fonts, mermaid and its dependency tree) without the license texts their
licenses require. Every affected ZIP now carries a licenses/ directory:

- licenses/THIRD-PARTY-NOTICES.txt is generated from the esbuild
  metafile (packages/plugins/third-party-licenses.mjs), so the notice
  list is derived from what actually lands in plugin.js and cannot
  drift the way a hand-maintained list would.
- drawio additionally extracts the upstream LICENSE from the pinned
  release tarball (Apache-2.0 requires the text with redistribution);
  the extraction guard also heals vendor/ caches from before this
  change. The CI fast path (no vendor fetch, no ZIP) is unchanged.
- excalidraw additionally commits curated texts (MIT for Excalidraw,
  per-font OFL-1.1/MIT with each font's own copyright statement, plus
  a FONT-NOTICES.md attribution table), because neither the npm
  package nor upstream ships any license files for them.

The api-side package validator accepts additional ZIP entries, so
installed plugins are unaffected beyond the new files.

Closes #345

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012aoPvnakfBP28nAfijgUY9

.claude/settings.json

@@ -0,0 +1,24 @@
+{
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash|Grep",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "/Users/stwaidele/.local/bin/graphify hook-guard search"
+          }
+        ]
+      },
+      {
+        "matcher": "Read|Glob",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "/Users/stwaidele/.local/bin/graphify hook-guard read"
+          }
+        ]
+      }
+    ]
+  }
+}

.gitea/workflows/cd.yml

@@ -68,7 +68,7 @@ jobs:
 
       - name: Pull and restart the Test stack
         run: |
-          ssh deploy@$DEPLOY_HOST 'cd /home/DOCKER/dorfteich-test \
+          ssh deploy@$DEPLOY_HOST 'cd /srv/DOCKER/dorfteich-test \
             && docker compose pull --quiet && docker compose up -d --remove-orphans \
             && docker compose ps'
 
@@ -86,7 +86,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version-file: .node-version
           cache: pnpm
 
       - name: Install dependencies
@@ -138,6 +138,6 @@ jobs:
 
       - name: Pull and restart the Int stack
         run: |
-          ssh deploy@$DEPLOY_HOST 'cd /home/DOCKER/dorfteich-int \
+          ssh deploy@$DEPLOY_HOST 'cd /srv/DOCKER/dorfteich-int \
             && docker compose pull --quiet && docker compose up -d --remove-orphans \
             && docker compose ps'

.gitea/workflows/ci.yml

@@ -38,18 +38,112 @@ jobs:
       - name: Check out repository
         uses: actions/checkout@v4
 
+      # Fails if a real .env (anything but .env.example) is ever tracked, or
+      # if a tracked file matches an obvious secret pattern (issue #198).
+      # .env.example is the authoritative reference; real values never enter
+      # the repository (docs/self-hosting/README.md).
+      - name: No tracked .env files or secret material
+        run: |
+          set -euo pipefail
+          bad_env=$(git ls-files | grep -E '(^|/)\.env(\.[^/]*)?$' | grep -v '\.env\.example$' || true)
+          if [ -n "$bad_env" ]; then
+            echo "tracked .env file(s) — only .env.example may be tracked:"
+            echo "$bad_env"
+            exit 1
+          fi
+          secrets=$(git grep -nIE -e '-----BEGIN [A-Z ]*PRIVATE KEY-----|AKIA[0-9A-Z]{16}|ghp_[A-Za-z0-9]{36}|glpat-[A-Za-z0-9_-]{20}|xox[baprs]-[0-9A-Za-z-]{10}' -- . || true)
+          if [ -n "$secrets" ]; then
+            echo "tracked file matches a secret pattern:"
+            echo "$secrets"
+            exit 1
+          fi
+
+      # One authoritative Node version (issue #236): `.node-version` is the
+      # pin; every Dockerfile image tag and the engines floor must match it
+      # exactly, and workflows select Node only through node-version-file.
+      # Raising Node = update .node-version, every `FROM node:` tag and the
+      # engines floor in ONE commit (procedure: docs/architecture/operations.md
+      # §Update strategy). The bracketed grep pattern keeps this step from
+      # matching its own source (same trick as the secret fence above).
+      - name: Node version pin is consistent
+        run: |
+          set -euo pipefail
+          ver="$(cat .node-version)"
+          echo "pinned Node version: $ver"
+          bad=0
+          for f in apps/*/Dockerfile; do
+            if grep '^FROM node:' "$f" | grep -v "node:${ver}-alpine"; then
+              echo "$f pins a different Node image than node:${ver}-alpine"
+              bad=1
+            fi
+          done
+          if grep -rn "node-version[:] " .gitea/workflows; then
+            echo "workflows must use node-version-file, not a literal version"
+            bad=1
+          fi
+          if grep -rnE 'node:[0-9][^ ]*-alpine' .gitea/workflows | grep -v "node:${ver}-alpine"; then
+            echo "a workflow references a different node image than node:${ver}-alpine"
+            bad=1
+          fi
+          if ! grep -q "\"node\": \">=${ver}\"" package.json; then
+            echo "package.json engines floor does not match ${ver}"
+            bad=1
+          fi
+          exit "$bad"
+
+      # Third-party deploy images are pinned by digest (issue #203): every
+      # image in the deploy compose that is not one of our own
+      # (${IMAGE_PREFIX}…) must carry @sha256 — the tag stays for
+      # readability, the digest decides what runs. Update procedure:
+      # deploy/stages.md §Third-party image digests. compose.dev.yml is a
+      # local convenience, deliberately not held to this.
+      - name: Third-party compose images are digest-pinned
+        run: |
+          set -euo pipefail
+          bad=$(grep -hE '^ *image: ' deploy/compose/docker-compose.yml | grep -v 'IMAGE_PREFIX' | grep -v '@sha256:' || true)
+          if [ -n "$bad" ]; then
+            echo "third-party image reference(s) without a digest:"
+            echo "$bad"
+            exit 1
+          fi
+
+      # A fresh named volume inherits the ownership of the image directory it
+      # is mounted over. Every /data/… path the api image defaults to must
+      # therefore be pre-created AND chowned to `node`, or the non-root user
+      # cannot write to it — found on a real deploy in #303, where the env
+      # entry was added but the mkdir/chown line was not.
+      - name: api image pre-creates its data directories node-owned
+        run: |
+          set -euo pipefail
+          dirs=$(grep -oE '[A-Z_]+_DIR=/data/[a-z]+' apps/api/Dockerfile | cut -d= -f2 | sort -u)
+          bad=0
+          for d in $dirs; do
+            grep -q "mkdir -p .*$d" apps/api/Dockerfile || {
+              echo "$d is not pre-created in apps/api/Dockerfile"; bad=1; }
+            grep -q "chown -R node:node .*$d" apps/api/Dockerfile || {
+              echo "$d is not chowned to node in apps/api/Dockerfile"; bad=1; }
+          done
+          exit "$bad"
+
       - name: Set up pnpm
         uses: pnpm/action-setup@v4
 
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version-file: .node-version
           cache: pnpm
 
       - name: Install dependencies
         run: pnpm install --frozen-lockfile
 
+      # License allowlist gate (issue #202): fails when any dependency's
+      # license falls outside the documented policy in
+      # scripts/check-licenses.mjs (which is also where the reasoning and
+      # per-package exceptions live).
+      - name: License allowlist
+        run: pnpm licenses list --json | node scripts/check-licenses.mjs
+
       # Build first: package type checks resolve @dorfteich/shared through
       # its built dist, and i18n:check imports the built helpers.
       - name: Build all packages
@@ -99,7 +193,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version-file: .node-version
           cache: pnpm
 
       - name: Install dependencies
@@ -116,7 +210,16 @@ jobs:
 
       - name: Start api, collab, and static web server
         run: |
-          (cd apps/api && PORT=3001 node dist/main.js > /tmp/api.log 2>&1 &)
+          # VS_NFD_MODE=marked: the marking pack and the a11y admin scan
+          # cover the marked state (issue #244); mode off is covered by
+          # local full runs and the marking pack's off-assertions there.
+          (cd apps/api && PORT=3001 VS_NFD_MODE=marked node dist/main.js > /tmp/api.log 2>&1 &)
+          # Second api on the SAME database with VS_NFD_MODE=hidden: the
+          # marking pack's hidden half runs against it via its own static
+          # server (issue #245); the mode is env-only, so sharing the db is
+          # exactly the deploy semantics.
+          (cd apps/api && PORT=3006 VS_NFD_MODE=hidden MIGRATE_ON_START=false node dist/main.js > /tmp/api-hidden.log 2>&1 &)
+          (PORT=5176 API_TARGET=http://127.0.0.1:3006 node scripts/e2e-static-server.mjs > /tmp/web-hidden.log 2>&1 &)
           (cd apps/collab && PORT=3002 node dist/index.js > /tmp/collab.log 2>&1 &)
           (PORT=5173 COLLAB_TARGET=http://127.0.0.1:3002 node scripts/e2e-static-server.mjs > /tmp/web.log 2>&1 &)
           for i in $(seq 1 30); do
@@ -242,6 +345,16 @@ jobs:
           E2E_BASE_URL=http://localhost:5173 \
             pnpm --filter @dorfteich/web exec playwright test e2e/social.spec.ts
 
+      - name: Reset login rate limit before admin-settings pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run admin-settings pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/admin-settings.spec.ts
+
       - name: Reset login rate limit before admin-quotas pack
         run: |
           echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
@@ -262,6 +375,18 @@ jobs:
           E2E_BASE_URL=http://localhost:5173 \
             pnpm --filter @dorfteich/web exec playwright test e2e/admin-users.spec.ts
 
+      - name: Reset login rate limit before invitations pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      # Invitations (issue #332) need the mail catcher like the auth pack:
+      # the invite link and the follow-up verification both travel by mail.
+      - name: Run invitations pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 E2E_MAILPIT_URL=http://mailpit:8025 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/invitations.spec.ts
+
       - name: Reset login rate limit before permission-matrix pack
         run: |
           echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
@@ -366,6 +491,76 @@ jobs:
           E2E_BASE_URL=http://localhost:5173 \
             pnpm --filter @dorfteich/web exec playwright test e2e/backlinks.spec.ts
 
+      - name: Reset login rate limit before page-tree pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run page-tree pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/page-tree.spec.ts
+
+      - name: Reset login rate limit before graph pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run graph pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/graph.spec.ts
+
+      - name: Reset login rate limit before favorites pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run favorites pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/favorites.spec.ts
+
+      - name: Reset login rate limit before settings-nav pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run settings-nav pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/settings-nav.spec.ts
+
+      - name: Reset login rate limit before tasks pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run tasks pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/tasks.spec.ts
+
+      - name: Reset login rate limit before create-missing-page pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run create-missing-page pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/create-missing-page.spec.ts
+
+      - name: Reset login rate limit before vault-import pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      - name: Run vault-import pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/import-vault.spec.ts
+
       - name: Reset login rate limit before search pack
         run: |
           echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
@@ -451,6 +646,57 @@ jobs:
             sleep 2
           done
 
+      # Six logins per run since #180 doubled the scans (3 contexts × light/
+      # dark, limit is 10/min) → reset first (see note above).
+      - name: Reset login rate limit before a11y pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      # WCAG-A/AA-Regressionsschutz (issue #171): axe-Scan der Kernscreens,
+      # seit #180 in beiden Farbschemata.
+      - name: Run a11y pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/a11y.spec.ts
+
+      # Das a11y-Pack kostet seit #301 einen Login mehr (der Reflow-Zaun);
+      # damit reicht das Budget nicht mehr bis in die VS-NfD-Packs → hier
+      # zusätzlich zurücksetzen (siehe Hinweis oben).
+      - name: Reset login rate limit before the VS-NfD packs
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      # VS-NfD-Markierungen im Modus `marked` (issue #244).
+      - name: Run VS-NfD marking pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 E2E_VS_NFD_MODE=marked \
+            pnpm --filter @dorfteich/web exec playwright test e2e/vs-nfd-marking.spec.ts
+
+      # Ausblendung + Policy-Hinweis im Modus `hidden` (issue #245).
+      - name: Run VS-NfD hidden pack
+        run: |
+          for i in $(seq 1 30); do
+            curl -sf http://localhost:3006/api/v1/readyz >/dev/null && break
+            sleep 2
+          done
+          E2E_BASE_URL=http://localhost:5176 E2E_VS_NFD_MODE=hidden \
+            pnpm --filter @dorfteich/web exec playwright test e2e/vs-nfd-marking.spec.ts
+
+      # The marking pack's extra login on top of the six a11y logins pushes
+      # the theme pack over the 10/min login limit — reset again (#244).
+      - name: Reset login rate limit before theme pack
+        run: |
+          echo "DELETE FROM rate_limits WHERE key LIKE 'login%';" | \
+            pnpm --filter @dorfteich/api exec prisma db execute --stdin --url "$DATABASE_URL"
+
+      # Hell/Dunkel/System-Umschalter (issue #180).
+      - name: Run theme pack
+        run: |
+          E2E_BASE_URL=http://localhost:5173 \
+            pnpm --filter @dorfteich/web exec playwright test e2e/theme.spec.ts
+
       - name: Run setup wizard pack
         run: |
           E2E_BASE_URL=http://localhost:5175 E2E_SETUP=1 \
@@ -484,7 +730,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version-file: .node-version
           cache: pnpm
 
       - name: Install dependencies
@@ -508,13 +754,16 @@ jobs:
       # image has no iproute2). Sharing the netns means no published ports.
       - name: Start pinned pandoc + Gotenberg sidecars
         run: |
-          # Clear any leftovers from an earlier interrupted run so the named
-          # containers never collide, and nothing leaks on the shared host.
-          docker rm -f fidelity-pandoc fidelity-gotenberg 2>/dev/null || true
+          # Sidecar names carry THIS job container's id: parallel runs on the
+          # shared host must not collide on a fixed name (a fixed-name rm -f
+          # here even killed a sibling run's live sidecars — run 547).
           JOB_ID=$(cat /etc/hostname)
-          docker run -d --name fidelity-pandoc \
+          echo "PANDOC_NAME=fidelity-pandoc-${JOB_ID}" >> "$GITHUB_ENV"
+          echo "GOTENBERG_NAME=fidelity-gotenberg-${JOB_ID}" >> "$GITHUB_ENV"
+          docker rm -f "fidelity-pandoc-${JOB_ID}" "fidelity-gotenberg-${JOB_ID}" 2>/dev/null || true
+          docker run -d --name "fidelity-pandoc-${JOB_ID}" \
             --network "container:${JOB_ID}" pandoc/core:3.6 server
-          docker run -d --name fidelity-gotenberg \
+          docker run -d --name "fidelity-gotenberg-${JOB_ID}" \
             --network "container:${JOB_ID}" gotenberg/gotenberg:8
           for i in $(seq 1 30); do
             curl -sf http://localhost:3030/version >/dev/null && break
@@ -538,15 +787,15 @@ jobs:
       - name: Dump sidecar logs on failure
         if: failure()
         run: |
-          echo '--- pandoc ---'; docker logs fidelity-pandoc 2>&1 | tail -30 || true
-          echo '--- gotenberg ---'; docker logs fidelity-gotenberg 2>&1 | tail -30 || true
+          echo '--- pandoc ---'; docker logs "$PANDOC_NAME" 2>&1 | tail -30 || true
+          echo '--- gotenberg ---'; docker logs "$GOTENBERG_NAME" 2>&1 | tail -30 || true
 
       # Always tear the sidecars down — they run on the shared runner host, so a
       # leaked (especially Chromium-backed Gotenberg) container would waste its
-      # memory until the next run and break re-runs on the container name.
+      # memory until the next run.
       - name: Stop sidecars
         if: always()
-        run: docker rm -f fidelity-pandoc fidelity-gotenberg 2>/dev/null || true
+        run: docker rm -f "$PANDOC_NAME" "$GOTENBERG_NAME" 2>/dev/null || true
 
   images:
     name: Build container images

.gitea/workflows/drill.yml

@@ -1,8 +1,11 @@
 # Monthly restore drill (ADR 0015, issue #87): restores the latest backup
 # set of the drilled stage into a scratch environment on the runner's Docker
 # daemon (the stage host), verifies it, and logs the outcome as a comment on
-# the pinned "Restore drills" issue. Pre-go-live the drilled stage is Test;
-# switch DRILL_SOURCE_VOLUME to the Prod backups volume at go-live (#89).
+# the pinned "Restore drills" issue. Since go-live (2026-07-12, #89) the
+# drilled stage is Prod; the runner on ONE holds the dorfteich-prod_backups
+# volume. TAG stays `test` on purpose: it only selects the drill-harness
+# images (backup + api) that perform and verify the restore, and a forward
+# schema restores a Prod set fine — it is not a claim about the Prod release.
 
 name: Restore drill
 
@@ -18,7 +21,7 @@ on:
 
 env:
   IMAGE_BASE: gitea.101010.cloud/stwaidele/dorfteich
-  DRILL_SOURCE_VOLUME: dorfteich-test_backups
+  DRILL_SOURCE_VOLUME: dorfteich-prod_backups
   DRILL_LOG_ISSUE: '98'
 
 jobs:
@@ -52,7 +55,7 @@ jobs:
           } > comment.md
           # JSON-encode via a node container — the runner image guarantees
           # only git/curl/docker, not python or node.
-          docker run --rm -i node:22.15-alpine node -e \
+          docker run --rm -i node:22.15.1-alpine node -e \
             'const fs=require("fs");process.stdout.write(JSON.stringify({body:fs.readFileSync(0,"utf8")}))' \
             < comment.md > comment.json
           curl -sf -X POST \

.gitea/workflows/prod-deploy.yml

@@ -38,13 +38,13 @@ jobs:
       - name: Set up SSH
         run: |
           mkdir -p ~/.ssh && chmod 700 ~/.ssh
-          printf '%s\n' "${{ secrets.DEPLOY_SSH_KEY_TEST }}" > ~/.ssh/id_ed25519
+          printf '%s\n' "${{ secrets.DEPLOY_SSH_KEY_PROD }}" > ~/.ssh/id_ed25519
           chmod 600 ~/.ssh/id_ed25519
           printf '%s\n' "${{ secrets.DEPLOY_HOST_KEY }}" > ~/.ssh/known_hosts
 
       - name: Pin the version and restart the Prod stack
         run: |
-          ssh deploy@$DEPLOY_HOST "cd /home/DOCKER/dorfteich-prod \
+          ssh deploy@$DEPLOY_HOST "cd /srv/DOCKER/dorfteich-prod \
             && sed -i 's/^TAG=.*/TAG=$VERSION/' .env \
             && docker compose pull --quiet && docker compose up -d --remove-orphans \
             && docker compose ps"

.gitea/workflows/release.yml

@@ -38,6 +38,62 @@ jobs:
             docker push $IMAGE_BASE-$app:$TAG
           done
 
+      # Supply-chain artefacts (issue #202): one CycloneDX SBOM per release
+      # image, one for the pnpm workspace, plus the full license report —
+      # attached as build artefacts of this run BEFORE the release is
+      # published, so a red gate stops the release. Mechanics dictated by
+      # the runner (the job talks to the HOST daemon, so bind mounts of
+      # workspace paths resolve on the host and go nowhere): files travel
+      # into the pinned syft container via `docker cp` (an API stream), and
+      # images via `docker save` to a tar copied the same way — syft cannot
+      # read a tar from stdin (not seekable).
+      - name: Generate SBOMs
+        run: |
+          set -euo pipefail
+          TAG=${GITHUB_REF_NAME}
+          SYFT=anchore/syft:v1.33.0
+          mkdir -p supply-chain sbom-src
+          cp pnpm-lock.yaml package.json sbom-src/
+          c=$(docker create $SYFT scan dir:/src --source-name dorfteich-workspace --source-version "$TAG" -o cyclonedx-json=/out.json)
+          docker cp sbom-src "$c:/src"
+          docker start -a "$c"
+          docker cp "$c:/out.json" supply-chain/sbom-workspace-$TAG.cdx.json
+          docker rm "$c" > /dev/null
+          for app in web api collab backup; do
+            docker save $IMAGE_BASE-$app:$TAG -o image.tar
+            c=$(docker create $SYFT scan docker-archive:/image.tar --source-name dorfteich-$app --source-version "$TAG" -o cyclonedx-json=/out.json)
+            docker cp image.tar "$c:/image.tar"
+            docker start -a "$c"
+            docker cp "$c:/out.json" supply-chain/sbom-image-$app-$TAG.cdx.json
+            docker rm "$c" > /dev/null
+            rm image.tar
+          done
+          ls -l supply-chain/
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: License report and allowlist gate
+        run: |
+          set -euo pipefail
+          pnpm licenses list --json > supply-chain/licenses-${GITHUB_REF_NAME}.json
+          node scripts/check-licenses.mjs < supply-chain/licenses-${GITHUB_REF_NAME}.json
+
+      - name: Attach supply-chain artefacts
+        uses: actions/upload-artifact@v3
+        with:
+          name: supply-chain-${{ github.ref_name }}
+          path: supply-chain/
+
       - name: Generate release notes and publish the release
         run: |
           TAG=${GITHUB_REF_NAME}
@@ -54,7 +110,7 @@ jobs:
               echo '_No database migrations in this release._'
             fi
           } > notes.md
-          TAG=$TAG docker run --rm -i -e TAG node:22.15-alpine node -e \
+          TAG=$TAG docker run --rm -i -e TAG node:22.15.1-alpine node -e \
             'const fs=require("fs");const body=fs.readFileSync(0,"utf8");process.stdout.write(JSON.stringify({tag_name:process.env.TAG,name:process.env.TAG,body}))' \
             < notes.md > release.json
           curl -sf -X POST \

.gitignore

@@ -14,3 +14,6 @@ apps/api/data/
 # Font catalog WOFF2 + generated stylesheet — fetched at build time
 # (ADR 0016, deploy/fonts/build-fonts.mjs), never committed.
 apps/web/public/fonts/
+
+# graphify knowledge graph (generated)
+graphify-out/

.node-version

@@ -0,0 +1 @@
+22.15.1

.prettierignore

@@ -14,3 +14,9 @@ fixtures/import/*.src.html
 # Export fidelity corpus (issue #69): the round-trip snapshots must stay exactly
 # as pandoc reads the exported document back — Prettier would break them.
 fixtures/export/*.expected.md
+packages/plugins/*/vendor/
+# Agent/tool config generated by Claude Code + `graphify claude install`
+# (regenerated on demand, not hand-formatted source) — keep out of Prettier so
+# a re-install never breaks the lint gate.
+CLAUDE.md
+.claude/

CLAUDE.md

@@ -0,0 +1,29 @@
+## Barrierefreiheit (verbindlich, ADR 0017)
+
+Jede UI-Änderung wird von Anfang an barrierefrei entwickelt (WCAG 2.1
+AA) — nicht nachträglich. Kurzfassung; Details und Begründung in
+`docs/architecture/adr/0017-accessibility-by-default.md`:
+
+- **Bausteine wiederverwenden:** `IconButton` (erzwungener Name),
+  `Field` (Label + Fehler-Verdrahtung), `useModalFocus` für Dialoge
+  (Trap/Initialfokus/Rückgabe + `aria-labelledby`). Keine Parallelbauten.
+- **Tastatur zuerst:** alles erreichbar/bedienbar, Fokus sichtbar,
+  Escape schließt, kein Fokusverlust; Einzeltasten-Shortcuts respektieren
+  `lib/single-key-shortcuts.ts`.
+- **Name/Rolle/Wert:** korrekte Rollen, lokalisierte (de+en) Labels,
+  Zustände via aria-*; dekorative Icons `aria-hidden`.
+- **BEIDE Renderpfade:** Editor-/NodeView-Pfad UND docToHtml/Server-Pfad
+  gleichwertig behandeln (Cache rollt lazy aus).
+- **Kontrast/Farbe:** Tokens nutzen (Text ≥ 4,5:1, UI ≥ 3:1;
+  `--color-border-input` für Feldränder; `--color-favorite` nur Icons);
+  Farbe nie als einziges Merkmal.
+- **Reflow:** kein seitenweites Horizontal-Scrollen bei 320 px
+  (`min-width: 0` an Flex-/Grid-Kindern nicht vergessen).
+- **Bewegung/Zeit:** `prefers-reduced-motion` respektieren, keine zu
+  kurzen Auto-Dismiss-Zeiten.
+- **CI-Pack pflegen:** neue Kern-Screens in `apps/web/e2e/a11y.spec.ts`
+  aufnehmen; die Allowlist bleibt leer bzw. nur mit Begründung.
+- Neue aria-Labels können bestehende `getByLabel`-e2e-Locator mehrdeutig
+  machen — betroffene Specs mit anpassen (scopen), nicht das Label opfern.
+
+Verstöße gelten in Review und Abnahme als Funktionsfehler.

README.md

@@ -32,10 +32,23 @@ offline support.
   first-run setup wizard yields a working instance. Start here:
   [`docs/self-hosting/README.md`](docs/self-hosting/README.md).
 
+## Documentation
+
+- **What is Dorfteich?** — [`docs/features.md`](docs/features.md)
+- **Manuals** (user / pond admin / site admin / API / MCP) —
+  [`docs/manual/`](docs/manual/README.md), auf Deutsch:
+  [`docs/de/`](docs/de/manual/README.md)
+- **Extending it** (plugins, core) —
+  [`docs/developer/extending.md`](docs/developer/extending.md)
+- **Running it** — [`docs/self-hosting/`](docs/self-hosting/README.md)
+- **How it works inside** — [`docs/architecture/`](docs/architecture/README.md)
+
 ## Repository layout
 
 | Path                 | Contents                                                                                                                           |
-| -------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
+| -------------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
+| `docs/manual/`       | User-facing manuals: user, pond-admin, site-admin, API, and MCP guides (start at [`docs/manual/README.md`](docs/manual/README.md)) |
+| `docs/developer/`    | Extending Dorfteich: plugin development and core contributions                                                                     |
 | `docs/architecture/` | Architecture documentation: ADRs, data model, permission model, collaboration and plugin concepts, deployment and operations       |
 | `docs/self-hosting/` | Install, update, backup, and troubleshooting guide for running your own instance                                                   |
 | `apps/`              | Application packages (web frontend, API server, collaboration server) — created as implementation proceeds                         |
@@ -60,9 +73,10 @@ imported as `@dorfteich/shared` — never copy code between apps.
 
 ## Status
 
-The project is in the architecture and backlog phase. Implementation stories
-are tracked as issues in this repository. Start reading at
-[`docs/architecture/README.md`](docs/architecture/README.md).
+Feature-complete for a 1.0: collaboration, permissions, import/export,
+plugins, public REST API + MCP, backups with off-host copies and in-app
+restore — all shipped and release-gated. Work is tracked as issues in
+this repository.
 
 ## Contributing
 

apps/api/Dockerfile

@@ -1,7 +1,7 @@
 # Build context is the repository root (workspace build):
 #   docker build -f apps/api/Dockerfile .
 
-FROM node:22.15-alpine AS build
+FROM node:22.15.1-alpine AS build
 WORKDIR /repo
 RUN npm install -g pnpm@11
 COPY pnpm-workspace.yaml pnpm-lock.yaml package.json tsconfig.base.json ./
@@ -21,25 +21,27 @@ RUN pnpm install --frozen-lockfile --filter @dorfteich/api... \
   # needed for migrate-on-start) at /out.
   && pnpm --filter @dorfteich/api deploy --prod --legacy /out \
   && cp -r apps/api/dist /out/dist \
+  && cp -r apps/api/assets /out/assets \
   && cp -r /repo/fonts /out/fonts
 
-FROM node:22.15-alpine
+FROM node:22.15.1-alpine
 ARG APP_VERSION=0.0.0-dev
 # Default the data dirs to the writable, node-owned locations created below, so
 # the image works out of the box even where compose does not set them; compose
 # still mounts named volumes here for persistence (UPLOADS_DIR/PLUGINS_DIR).
-ENV NODE_ENV=production APP_VERSION=${APP_VERSION} UPLOADS_DIR=/data/uploads PLUGINS_DIR=/data/plugins SECRETS_FILE=/data/secrets/secrets.env BACKUPS_DIR=/data/backups
+ENV NODE_ENV=production APP_VERSION=${APP_VERSION} UPLOADS_DIR=/data/uploads PLUGINS_DIR=/data/plugins CUSTOM_FONTS_DIR=/data/fonts BRANDING_DIR=/data/branding SECRETS_FILE=/data/secrets/secrets.env BACKUPS_DIR=/data/backups
 WORKDIR /app
 COPY --from=build --chown=node:node /out /app
 # Generate the Prisma client for this image's platform.
 RUN node node_modules/prisma/build/index.js generate
-# A fresh named volume mounted at /data/uploads or /data/plugins is created
+# A fresh named volume mounted at /data/uploads, /data/plugins, /data/fonts
+# or /data/branding is created
 # root-owned; pre-creating them here (Docker copies an image directory's
 # ownership into a new volume on first mount) lets the non-root `node` user
 # write to them. /data/backups is mounted read-only here, but pre-creating it
 # node-owned keeps the shared `backups` volume writable for the backup
 # sidecar even when the api container is the one that initializes it.
-RUN mkdir -p /data/uploads /data/plugins /data/secrets /data/backups && chown -R node:node /data/uploads /data/plugins /data/secrets /data/backups
+RUN mkdir -p /data/uploads /data/plugins /data/fonts /data/branding /data/secrets /data/backups && chown -R node:node /data/uploads /data/plugins /data/fonts /data/branding /data/secrets /data/backups
 USER node
 EXPOSE 3000
 HEALTHCHECK --interval=30s --timeout=3s --retries=3 \

apps/api/assets/README.md

@@ -0,0 +1,45 @@
+# Runtime assets
+
+## `reference-vs-nfd.docx` / `reference-vs-nfd.odt` (issue #209, ADR 0022)
+
+Pandoc reference documents for the DOCX/ODT export of a **classified**
+page: their page setup defines a header and footer carrying the VS-NfD
+marking, which pandoc copies into its output — so the marking repeats on
+every page in Word and LibreOffice and is not deletable body text.
+Unclassified exports pass no reference document and are unchanged.
+
+These are **derived binaries — never edit them by hand.** Source of truth
+is `../scripts/gen-classified-reference-docs.mjs`: it takes the default
+reference documents of the pinned sidecar (`pandoc/core:3.6`, the exact
+image the stages run) and injects the header/footer, with the wording from
+`classificationMarking()` in `@dorfteich/shared` (single source, ADR
+0022). Regenerate — after a pandoc pin bump, a wording change, or a layout
+tweak in the script — with Docker running:
+
+```sh
+pnpm --filter @dorfteich/shared build   # the script imports the wording
+node apps/api/scripts/gen-classified-reference-docs.mjs
+```
+
+Commit script and binaries together. The fidelity suite
+(`export.fidelity.test.ts`) asserts against the real pinned pandoc that a
+marked export carries the header/footer parts and an unmarked one does
+not.
+
+### Per-page verification in the office suites
+
+After regenerating, confirm the marking repeats on **every** page of a
+multi-page export (not just structurally in the XML):
+
+1. Produce a marked multi-page export (any classified page with a few
+   screens of text, exported to `.docx` and `.odt`).
+2. **LibreOffice** (scriptable):
+   `soffice --headless --convert-to pdf <file>` and check every PDF page
+   shows the marking twice (header + footer) — e.g. with `pypdf`.
+3. **Word**: open the `.docx`, check header and footer on every page
+   (print preview). Word's AppleScript/sandbox makes this hard to script —
+   this step is a quick manual look.
+
+Last verified 2026-07-31 (pandoc 3.6 output): LibreOffice 25.8, both
+formats, 5/5 pages with 2 markings each. Word: manual check pending —
+sample files in the workspace under `doku/209-marked-sample.docx/.odt`.

apps/api/package.json

@@ -18,6 +18,7 @@
   "dependencies": {
     "@dorfteich/plugin-sdk": "workspace:*",
     "@dorfteich/shared": "workspace:*",
+    "@modelcontextprotocol/sdk": "^1.29.0",
     "@nestjs/common": "^11.0.0",
     "@nestjs/core": "^11.0.0",
     "@nestjs/platform-express": "^11.0.0",
@@ -29,6 +30,7 @@
     "fflate": "^0.8.3",
     "fractional-indexing": "^4.0.0",
     "i18next": "^26.3.4",
+    "jose": "^6.2.4",
     "jsdom": "^26.1.0",
     "multer": "^2.1.1",
     "nestjs-pino": "^4.3.0",

apps/api/prisma/migrations/20260712020000_api_tokens/migration.sql

@@ -0,0 +1,27 @@
+-- CreateEnum
+CREATE TYPE "ApiTokenScope" AS ENUM ('READ', 'WRITE');
+
+-- CreateTable
+CREATE TABLE "api_tokens" (
+    "id" TEXT NOT NULL,
+    "token_hash" TEXT NOT NULL,
+    "user_id" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "scope" "ApiTokenScope" NOT NULL,
+    "pond_ids" TEXT[] DEFAULT ARRAY[]::TEXT[],
+    "expires_at" TIMESTAMP(3),
+    "revoked_at" TIMESTAMP(3),
+    "last_used_at" TIMESTAMP(3),
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "api_tokens_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "api_tokens_token_hash_key" ON "api_tokens"("token_hash");
+
+-- CreateIndex
+CREATE INDEX "api_tokens_user_id_idx" ON "api_tokens"("user_id");
+
+-- AddForeignKey
+ALTER TABLE "api_tokens" ADD CONSTRAINT "api_tokens_user_id_fkey" FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/migrations/20260714000000_page_hierarchy/migration.sql

@@ -0,0 +1,8 @@
+-- AlterTable
+ALTER TABLE "pages" ADD COLUMN "parent_id" TEXT;
+
+-- CreateIndex
+CREATE INDEX "pages_parent_id_idx" ON "pages"("parent_id");
+
+-- AddForeignKey
+ALTER TABLE "pages" ADD CONSTRAINT "pages_parent_id_fkey" FOREIGN KEY ("parent_id") REFERENCES "pages"("id") ON DELETE SET NULL ON UPDATE CASCADE;

apps/api/prisma/migrations/20260714120000_conversion_job_options/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "conversion_jobs" ADD COLUMN "options" JSONB;

apps/api/prisma/migrations/20260716000000_page_favorites/migration.sql

@@ -0,0 +1,16 @@
+-- Personal page favorites (issue #132).
+
+CREATE TABLE "page_favorites" (
+    "user_id" TEXT NOT NULL,
+    "page_id" TEXT NOT NULL,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "page_favorites_pkey" PRIMARY KEY ("user_id", "page_id")
+);
+
+CREATE INDEX "page_favorites_page_id_idx" ON "page_favorites"("page_id");
+
+ALTER TABLE "page_favorites" ADD CONSTRAINT "page_favorites_user_id_fkey"
+    FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+ALTER TABLE "page_favorites" ADD CONSTRAINT "page_favorites_page_id_fkey"
+    FOREIGN KEY ("page_id") REFERENCES "pages"("id") ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/migrations/20260719223755_page_time_filter_indexes/migration.sql

@@ -0,0 +1,5 @@
+-- CreateIndex
+CREATE INDEX "pages_pond_id_created_at_idx" ON "pages"("pond_id", "created_at");
+
+-- CreateIndex
+CREATE INDEX "pages_pond_id_updated_at_idx" ON "pages"("pond_id", "updated_at");

apps/api/prisma/migrations/20260719224240_feed_tokens/migration.sql

@@ -0,0 +1,20 @@
+-- CreateTable
+CREATE TABLE "feed_tokens" (
+    "id" TEXT NOT NULL,
+    "token_hash" TEXT NOT NULL,
+    "user_id" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "last_used_at" TIMESTAMP(3),
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "feed_tokens_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "feed_tokens_token_hash_key" ON "feed_tokens"("token_hash");
+
+-- CreateIndex
+CREATE INDEX "feed_tokens_user_id_idx" ON "feed_tokens"("user_id");
+
+-- AddForeignKey
+ALTER TABLE "feed_tokens" ADD CONSTRAINT "feed_tokens_user_id_fkey" FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/migrations/20260719232202_page_mentions/migration.sql

@@ -0,0 +1,16 @@
+-- CreateTable
+CREATE TABLE "page_mentions" (
+    "page_id" TEXT NOT NULL,
+    "user_id" TEXT NOT NULL,
+
+    CONSTRAINT "page_mentions_pkey" PRIMARY KEY ("page_id","user_id")
+);
+
+-- CreateIndex
+CREATE INDEX "page_mentions_user_id_idx" ON "page_mentions"("user_id");
+
+-- AddForeignKey
+ALTER TABLE "page_mentions" ADD CONSTRAINT "page_mentions_page_id_fkey" FOREIGN KEY ("page_id") REFERENCES "pages"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "page_mentions" ADD CONSTRAINT "page_mentions_user_id_fkey" FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/migrations/20260730120000_drop_attachment_deleted_at/migration.sql

@@ -0,0 +1,4 @@
+-- Issue #194: attachments have exactly one deletion semantics (hard delete
+-- by sweep, purge, or manual removal) — the never-written soft-delete
+-- marker goes away.
+ALTER TABLE "attachments" DROP COLUMN "deleted_at";

apps/api/prisma/migrations/20260730140000_clear_trashed_search_vectors/migration.sql

@@ -0,0 +1,10 @@
+-- Issue #195, one-off backfill: the full-text index must hold no trashed
+-- content. Clears the search vector of every page that is trashed itself
+-- or lives in a trashed pond; the application keeps this invariant from
+-- now on (trash hooks + reindex paths).
+UPDATE page_content_cache c
+   SET search_vector = NULL
+  FROM pages p
+  LEFT JOIN ponds po ON po.id = p.pond_id
+ WHERE p.id = c.page_id
+   AND (p.deleted_at IS NOT NULL OR po.deleted_at IS NOT NULL);

apps/api/prisma/migrations/20260730170000_prune_conversion_job_payloads/migration.sql

@@ -0,0 +1,16 @@
+-- #233: conversion job payloads become prunable. The raw input/result bytes
+-- are transient; a daily job nulls them once a finished job passes
+-- `conversion.payloadRetentionDays` (default 30). The row survives for
+-- status/audit purposes.
+ALTER TABLE "conversion_jobs" ALTER COLUMN "input" DROP NOT NULL;
+
+-- Backfill: clear the payloads of jobs that already finished longer ago than
+-- the default period. Recently finished jobs keep their bytes so a pending
+-- download still works; the scheduled job picks them up when they age out.
+-- PENDING/RUNNING rows are untouched (the worker's stale-lock recovery may
+-- still re-run them).
+UPDATE "conversion_jobs"
+   SET "input" = NULL, "result" = NULL, "result_mime_type" = NULL
+ WHERE "status" IN ('SUCCEEDED', 'FAILED')
+   AND "updated_at" < now() - interval '30 days'
+   AND ("input" IS NOT NULL OR "result" IS NOT NULL);

apps/api/prisma/migrations/20260731090000_attachment_sha256/migration.sql

@@ -0,0 +1,5 @@
+-- #199: integrity hash for uploaded files. New uploads store the SHA-256 of
+-- their bytes at write time; existing rows are hashed by the nightly
+-- backfill (part of the orphan-file-sweep job), which reads the uploads
+-- volume — something this SQL migration cannot do.
+ALTER TABLE "attachments" ADD COLUMN "sha256" TEXT;

apps/api/prisma/migrations/20260731120000_page_classification/migration.sql

@@ -0,0 +1,8 @@
+-- #204 (ADR 0022): classification becomes first-class page metadata. The
+-- column is a marking, not a protection mechanism — permissions are
+-- untouched. NOT NULL with a default backfills every existing page to
+-- UNCLASSIFIED in the same statement.
+CREATE TYPE "PageClassification" AS ENUM ('UNCLASSIFIED', 'VS_NFD');
+
+ALTER TABLE "pages"
+  ADD COLUMN "classification" "PageClassification" NOT NULL DEFAULT 'UNCLASSIFIED';

apps/api/prisma/migrations/20260731150000_read_events/migration.sql

@@ -0,0 +1,23 @@
+-- #222 (ADR 0023): read-access trail for classified pages. Its own table —
+-- volume, purpose and legal basis differ from audit_log. No foreign keys:
+-- evidence must survive page purges and hard user deletions unchanged.
+-- Partitioning and retention follow in #224.
+CREATE TABLE "read_events" (
+    "id" TEXT NOT NULL,
+    "occurred_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "actor_id" TEXT,
+    "session_key" TEXT NOT NULL,
+    "page_id" TEXT,
+    "pond_id" TEXT NOT NULL,
+    "channel" TEXT NOT NULL,
+    "classification" TEXT NOT NULL,
+    "details" JSONB,
+
+    CONSTRAINT "read_events_pkey" PRIMARY KEY ("id")
+);
+
+CREATE INDEX "read_events_page_id_occurred_at_idx" ON "read_events"("page_id", "occurred_at");
+
+CREATE INDEX "read_events_actor_id_occurred_at_idx" ON "read_events"("actor_id", "occurred_at");
+
+CREATE INDEX "read_events_occurred_at_idx" ON "read_events"("occurred_at");

apps/api/prisma/migrations/20260731160000_read_events_dedup/migration.sql

@@ -0,0 +1,32 @@
+-- #223 (ADR 0023): dedup window for the read trail. Aligned buckets
+-- (floor(epoch / window)) with a unique (dedup_key, window_bucket) pair make
+-- concurrent duplicates collapse race-free at insert time.
+ALTER TABLE "read_events"
+  ADD COLUMN "dedup_key" TEXT,
+  ADD COLUMN "window_bucket" BIGINT,
+  ADD COLUMN "window_seconds" INTEGER;
+
+-- Backfill rows written between the #222 and #223 deploys under the default
+-- 5-minute window, then apply the window's own semantics retroactively:
+-- within one (key, bucket) pair only the FIRST event is the evidence row —
+-- exactly what the window would have recorded had it existed.
+UPDATE "read_events"
+   SET "dedup_key" = "session_key" || ':' || COALESCE("page_id", '-') || ':' || "channel",
+       "window_bucket" = FLOOR(EXTRACT(EPOCH FROM "occurred_at") / 300)::BIGINT,
+       "window_seconds" = 300
+ WHERE "dedup_key" IS NULL;
+
+DELETE FROM "read_events" keep
+ USING "read_events" first
+ WHERE keep."dedup_key" = first."dedup_key"
+   AND keep."window_bucket" = first."window_bucket"
+   AND (first."occurred_at" < keep."occurred_at"
+        OR (first."occurred_at" = keep."occurred_at" AND first."id" < keep."id"));
+
+ALTER TABLE "read_events"
+  ALTER COLUMN "dedup_key" SET NOT NULL,
+  ALTER COLUMN "window_bucket" SET NOT NULL,
+  ALTER COLUMN "window_seconds" SET NOT NULL;
+
+CREATE UNIQUE INDEX "read_events_dedup_key_window_bucket_key"
+  ON "read_events"("dedup_key", "window_bucket");

apps/api/prisma/migrations/20260731170000_read_events_partitioned/migration.sql

@@ -0,0 +1,76 @@
+-- #224 (ADR 0023): convert read_events to monthly RANGE partitions on
+-- occurred_at. Volume grows unbounded with use; retention then DROPs whole
+-- expired partitions instead of scanning deletes. The primary key gains the
+-- partition column (PostgreSQL requirement); the dedup unique pair
+-- (dedup_key, window_bucket) moves to PER-PARTITION unique indexes — a
+-- partitioned parent cannot carry it without the partition key. A bucket
+-- spanning a month boundary can therefore record one duplicate; documented
+-- in ADR 0023, over-recording is acceptable, gaps are not.
+--
+-- A DEFAULT partition catches rows outside every maintained range, so a
+-- lagging maintenance job can never make classified reads fail (the trail's
+-- hard-failure semantics would otherwise turn an ops miss into an outage).
+
+ALTER TABLE "read_events" RENAME TO "read_events_old";
+ALTER INDEX "read_events_pkey" RENAME TO "read_events_old_pkey";
+ALTER INDEX "read_events_dedup_key_window_bucket_key" RENAME TO "read_events_old_dedup_key";
+ALTER INDEX "read_events_page_id_occurred_at_idx" RENAME TO "read_events_old_page_idx";
+ALTER INDEX "read_events_actor_id_occurred_at_idx" RENAME TO "read_events_old_actor_idx";
+ALTER INDEX "read_events_occurred_at_idx" RENAME TO "read_events_old_at_idx";
+
+CREATE TABLE "read_events" (
+    "id" TEXT NOT NULL,
+    "occurred_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "actor_id" TEXT,
+    "session_key" TEXT NOT NULL,
+    "page_id" TEXT,
+    "pond_id" TEXT NOT NULL,
+    "channel" TEXT NOT NULL,
+    "classification" TEXT NOT NULL,
+    "details" JSONB,
+    "dedup_key" TEXT NOT NULL,
+    "window_bucket" BIGINT NOT NULL,
+    "window_seconds" INTEGER NOT NULL,
+
+    CONSTRAINT "read_events_pkey" PRIMARY KEY ("id", "occurred_at")
+) PARTITION BY RANGE ("occurred_at");
+
+-- Non-unique parent indexes propagate to every partition automatically.
+CREATE INDEX "read_events_page_id_occurred_at_idx" ON "read_events"("page_id", "occurred_at");
+CREATE INDEX "read_events_actor_id_occurred_at_idx" ON "read_events"("actor_id", "occurred_at");
+CREATE INDEX "read_events_occurred_at_idx" ON "read_events"("occurred_at");
+
+-- The safety-net partition, plus the current and the next month — the daily
+-- maintenance job (read-trail-maintenance) keeps creating months ahead and
+-- adds the same per-partition dedup index to each new one.
+CREATE TABLE "read_events_default" PARTITION OF "read_events" DEFAULT;
+CREATE UNIQUE INDEX "read_events_default_dedup_key"
+  ON "read_events_default"("dedup_key", "window_bucket");
+
+DO $$
+DECLARE
+  m DATE;
+  part TEXT;
+BEGIN
+  FOR i IN 0..1 LOOP
+    m := date_trunc('month', now())::date + (i || ' month')::interval;
+    part := 'read_events_y' || to_char(m, 'YYYY') || 'm' || to_char(m, 'MM');
+    EXECUTE format(
+      'CREATE TABLE %I PARTITION OF "read_events" FOR VALUES FROM (%L) TO (%L)',
+      part, m, m + interval '1 month');
+    EXECUTE format(
+      'CREATE UNIQUE INDEX %I ON %I ("dedup_key", "window_bucket")',
+      part || '_dedup_key', part);
+  END LOOP;
+END $$;
+
+INSERT INTO "read_events"
+  ("id", "occurred_at", "actor_id", "session_key", "page_id", "pond_id",
+   "channel", "classification", "details", "dedup_key", "window_bucket",
+   "window_seconds")
+SELECT "id", "occurred_at", "actor_id", "session_key", "page_id", "pond_id",
+       "channel", "classification", "details", "dedup_key", "window_bucket",
+       "window_seconds"
+  FROM "read_events_old";
+
+DROP TABLE "read_events_old";

apps/api/prisma/migrations/20260731190000_idp_claim_mapping/migration.sql

@@ -0,0 +1,9 @@
+-- #217 (ADR 0021): IdP claim mapping. Grants gain an origin so mapped rows
+-- are distinguishable from manual ones (the mapping only ever touches its
+-- own); the site-admin flag gains a "managed" marker so only a
+-- mapping-granted flag can be mapping-revoked.
+ALTER TABLE "role_grants"
+  ADD COLUMN "origin" TEXT NOT NULL DEFAULT 'manual';
+
+ALTER TABLE "users"
+  ADD COLUMN "is_site_admin_managed" BOOLEAN NOT NULL DEFAULT false;

apps/api/prisma/migrations/20260731210000_plugin_bundle_hash/migration.sql

@@ -0,0 +1,4 @@
+-- #232: SHA-256 of the installed bundle ZIP, observed at install time.
+-- NULL for plugins installed before this migration — the admin UI says so
+-- and a reinstall records it.
+ALTER TABLE "plugins" ADD COLUMN "bundle_hash" TEXT;

apps/api/prisma/migrations/20260801120000_custom_fonts/migration.sql

@@ -0,0 +1,45 @@
+-- #303: operator-uploaded font families (ADR 0016 §#303).
+-- The bytes live on disk under CUSTOM_FONTS_DIR; these rows record only what
+-- the upload form stated, because the api never parses the font file.
+
+CREATE TABLE "custom_fonts" (
+    "id" TEXT NOT NULL,
+    "family" TEXT NOT NULL,
+    "slug" TEXT NOT NULL,
+    "category" TEXT NOT NULL,
+    "licence" TEXT NOT NULL,
+    "licence_url" TEXT,
+    "uploaded_by" TEXT NOT NULL,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "custom_fonts_pkey" PRIMARY KEY ("id")
+);
+
+-- Both unique: `family` keeps `fonts.<slot>.family` in pond settings
+-- unambiguous, `slug` owns a directory under CUSTOM_FONTS_DIR.
+CREATE UNIQUE INDEX "custom_fonts_family_key" ON "custom_fonts"("family");
+CREATE UNIQUE INDEX "custom_fonts_slug_key" ON "custom_fonts"("slug");
+
+ALTER TABLE "custom_fonts" ADD CONSTRAINT "custom_fonts_uploaded_by_fkey"
+    FOREIGN KEY ("uploaded_by") REFERENCES "users"("id")
+    ON DELETE RESTRICT ON UPDATE CASCADE;
+
+CREATE TABLE "custom_font_weights" (
+    "id" TEXT NOT NULL,
+    "font_id" TEXT NOT NULL,
+    "weight" INTEGER NOT NULL,
+    "has_woff" BOOLEAN NOT NULL DEFAULT false,
+    "byte_size" INTEGER NOT NULL,
+
+    CONSTRAINT "custom_font_weights_pkey" PRIMARY KEY ("id")
+);
+
+CREATE UNIQUE INDEX "custom_font_weights_font_id_weight_key"
+    ON "custom_font_weights"("font_id", "weight");
+
+-- Deleting a family takes its weights with it; the files on disk are removed
+-- by the service in the same operation.
+ALTER TABLE "custom_font_weights" ADD CONSTRAINT "custom_font_weights_font_id_fkey"
+    FOREIGN KEY ("font_id") REFERENCES "custom_fonts"("id")
+    ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/migrations/20260805120000_invitations/migration.sql

@@ -0,0 +1,26 @@
+-- Peer invitations (issue #332): a user invites an e-mail address; the token
+-- allows exactly one registration even while registration is closed.
+
+-- CreateTable
+CREATE TABLE "invitations" (
+    "id" TEXT NOT NULL,
+    "inviter_id" TEXT NOT NULL,
+    "email" TEXT NOT NULL,
+    "token_hash" TEXT NOT NULL,
+    "expires_at" TIMESTAMP(3) NOT NULL,
+    "revoked_at" TIMESTAMP(3),
+    "accepted_at" TIMESTAMP(3),
+    "accepted_user_id" TEXT,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "invitations_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "invitations_token_hash_key" ON "invitations"("token_hash");
+
+-- CreateIndex
+CREATE INDEX "invitations_inviter_id_idx" ON "invitations"("inviter_id");
+
+-- AddForeignKey
+ALTER TABLE "invitations" ADD CONSTRAINT "invitations_inviter_id_fkey" FOREIGN KEY ("inviter_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

apps/api/prisma/schema.prisma

@@ -37,6 +37,11 @@ model User {
   displayName        String     @map("display_name")
   locale             String     @default("en")
   isSiteAdmin        Boolean    @default(false) @map("is_site_admin")
+  /// True when the flag was last SET by the IdP claim mapping (issue #217):
+  /// only then may the mapping revoke it again on a later login. A manual
+  /// admin toggle clears the marker, so hand-granted admins are never
+  /// demoted by a missing claim.
+  isSiteAdminManaged Boolean    @default(false) @map("is_site_admin_managed")
   /// Auto-watch preferences (issue #93): watch pages I create / comment on.
   autoWatchOwnPages  Boolean    @default(true) @map("auto_watch_own_pages")
   autoWatchOnComment Boolean    @default(true) @map("auto_watch_on_comment")
@@ -50,6 +55,9 @@ model User {
   identities     UserIdentity[]
   sessions       Session[]
   authTokens     AuthToken[]
+  apiTokens      ApiToken[]
+  feedTokens     FeedToken[]
+  mentionRows    PageMention[]
   ponds          Pond[]
   pages          Page[]
   attachments    Attachment[]
@@ -58,10 +66,36 @@ model User {
   comments       Comment[]
   watches        Watch[]
   notifications  Notification[]
+  favorites      PageFavorite[]
+  customFonts    CustomFont[]
+  invitations    Invitation[]   @relation("InvitationsSent")
 
   @@map("users")
 }
 
+/// Peer invitations (issue #332): a user invites an e-mail address; the
+/// token allows exactly one registration even while registration is
+/// closed. Only the SHA-256 hash of the token is stored (auth-tokens
+/// pattern); revoked/accepted rows are kept so the settings UI can show
+/// history. "Open" (pending, unexpired) rows count against the per-user
+/// quota `invitations.maxOpenPerUser`.
+model Invitation {
+  id             String    @id @default(uuid())
+  inviterId      String    @map("inviter_id")
+  email          String
+  tokenHash      String    @unique @map("token_hash")
+  expiresAt      DateTime  @map("expires_at")
+  revokedAt      DateTime? @map("revoked_at")
+  acceptedAt     DateTime? @map("accepted_at")
+  acceptedUserId String?   @map("accepted_user_id")
+  createdAt      DateTime  @default(now()) @map("created_at")
+
+  inviter User @relation("InvitationsSent", fields: [inviterId], references: [id], onDelete: Cascade)
+
+  @@index([inviterId])
+  @@map("invitations")
+}
+
 /// Persistent audit trail (issue #86, security.md §Logging): auth events and
 /// admin actions — grants, member roles, plugin installs, quota and settings
 /// changes, setup steps, manual job triggers. Written by AuditService, which
@@ -87,6 +121,52 @@ model AuditEntry {
   @@map("audit_log")
 }
 
+/// Read-access trail for classified pages (issue #222, ADR 0023): one row per
+/// read of a `VS_NFD` page, per channel. Separate from `audit_log` because
+/// volume, purpose and legal basis all differ. Deliberately WITHOUT foreign
+/// keys: evidence must survive a page purge and a hard user deletion — the
+/// ids stay as recorded (pseudonymous uuids), history is never rewritten.
+///
+/// In migrated databases the table is RANGE-partitioned by `occurred_at`
+/// (monthly, issue #224) — hence the composite id. The dedup unique pair
+/// lives per partition there (a partitioned parent cannot carry it without
+/// the partition key); `db push` test databases get it on the plain table.
+model ReadEvent {
+  id             String   @default(uuid())
+  occurredAt     DateTime @default(now()) @map("occurred_at")
+  /// Null = anonymous reader (public grant); `sessionKey` still names the
+  /// browsing session, so the anonymous marker is explicit, not an accident.
+  actorId        String?  @map("actor_id")
+  /// `session:<id>` for cookie sessions, `token:<id>` for PATs, `job:<id>`
+  /// for background builds (account data export), `anon` for anonymous
+  /// visitors — the dedup-window key basis (#223).
+  sessionKey     String   @map("session_key")
+  pageId         String?  @map("page_id")
+  pondId         String   @map("pond_id")
+  /// Which read surface fired: `page_view` | `no_js_shell` | `public_api` |
+  /// `attachment` | `export` | `collab_join` (READ_CHANNELS union in code).
+  channel        String
+  /// Classification at read time — a later reclassification must not
+  /// rewrite history (ADR 0023).
+  classification String
+  details        Json?
+  /// Dedup window (issue #223): `<sessionKey>:<pageId|->:<channel>` plus the
+  /// aligned bucket `floor(epoch / windowSeconds)`. The unique pair makes
+  /// concurrent duplicate reads collapse race-free (insert or P2002-skip).
+  dedupKey       String   @map("dedup_key")
+  windowBucket   BigInt   @map("window_bucket")
+  /// Window length the event was recorded under — the row itself states it
+  /// represents up to this many seconds, so the evidence is not overread.
+  windowSeconds  Int      @map("window_seconds")
+
+  @@id([id, occurredAt])
+  @@unique([dedupKey, windowBucket])
+  @@index([pageId, occurredAt])
+  @@index([actorId, occurredAt])
+  @@index([occurredAt])
+  @@map("read_events")
+}
+
 /// Threaded page comments (issue #91, data-model.md §Comments). Threads are
 /// one level deep: roots carry the optional document anchor and the resolve
 /// state, replies reference the root via `parentId`. Purging a page cascades
@@ -235,6 +315,10 @@ model RoleGrant {
   scopeType   GrantScopeType   @map("scope_type")
   scopeId     String?          @map("scope_id")
   effect      GrantEffect
+  /// `manual` (admin-created) or `idp` (written by the claim mapping,
+  /// issue #217). The mapping only ever creates and revokes ITS OWN rows —
+  /// manual grants are never touched, which is the documented precedence.
+  origin      String           @default("manual")
   createdBy   String           @map("created_by")
   createdAt   DateTime         @default(now()) @map("created_at")
 
@@ -250,13 +334,31 @@ model RoleGrant {
 /// the merged state Y.Doc, decoded by the API to derive `PageContentCache`
 /// on every save (issue #23). `sortKey` uses fractional indexing so pages
 /// can be reordered without rewriting siblings (sidebar reorder is #26).
+/// `parentId` nests pages into a tree (issue #106), mirroring the label
+/// hierarchy (max 6 levels, enforced in the service; cycles rejected at write
+/// time). Purely organizational: slugs stay flat and pond-unique, so moving a
+/// page never changes its URL or breaks wikilinks. Trashed pages keep their
+/// `parentId` (restore re-attaches to the nearest live ancestor, issue #107);
+/// `SetNull` is only the FK backstop — purge promotes children explicitly.
+/// VS-NfD marking level of a page (ADR 0022). Deliberately an enum on Page,
+/// not a label: instance-wide meaning, not user-deletable in routine content
+/// work, inherits down the tree (#205), reaches every output channel
+/// (#206–#212). It is a MARKING, not a protection mechanism — separation of
+/// levels happens outside the application (one instance per level).
+enum PageClassification {
+  UNCLASSIFIED
+  VS_NFD
+}
+
 model Page {
   id             String             @id @default(uuid())
   pondId         String             @map("pond_id")
+  parentId       String?            @map("parent_id")
   title          String
   slug           String
   ydocState      Bytes              @map("ydoc_state")
   sortKey        String             @map("sort_key")
+  classification PageClassification @default(UNCLASSIFIED)
   createdBy      String             @map("created_by")
   createdAt      DateTime           @default(now()) @map("created_at")
   updatedAt      DateTime           @updatedAt @map("updated_at")
@@ -264,20 +366,29 @@ model Page {
   deletedBy      String?            @map("deleted_by")
 
   pond                Pond                     @relation(fields: [pondId], references: [id])
+  parent              Page?                    @relation("PageHierarchy", fields: [parentId], references: [id], onDelete: SetNull)
+  children            Page[]                   @relation("PageHierarchy")
   creator             User                     @relation(fields: [createdBy], references: [id])
   updates             PageUpdate[]
   contentCache        PageContentCache?
   attachments         Attachment[]
   versions            PageVersion[]
   pendingContributors PagePendingContributor[]
+  mentionRows         PageMention[]
   labels              PageLabel[]
   outgoingLinks       PageLink[]               @relation("outgoingLinks")
   comments            Comment[]
   incomingLinks       PageLink[]               @relation("incomingLinks")
   conversionJobs      ConversionJob[]
+  favorites           PageFavorite[]
 
   @@unique([pondId, slug])
   @@index([pondId])
+  @@index([parentId])
+  // Time-filtered listings (issue #148): "pages of this pond created/updated
+  // since X" hit these instead of scanning the pond.
+  @@index([pondId, createdAt])
+  @@index([pondId, updatedAt])
   @@map("pages")
 }
 
@@ -331,6 +442,21 @@ model PageVersion {
 /// Collab flushes the current session's contributors here (deduplicated by the
 /// composite key); version creation on either side reads and clears it in the
 /// same transaction as writing the snapshot. Cascades on page purge (ADR 0013).
+/// Derived mention index (issue #151): one row per user currently
+/// mentioned in the page's document. Rewritten on every collab persist;
+/// the diff against the previous rows drives the `mentioned` notifications.
+model PageMention {
+  pageId String @map("page_id")
+  userId String @map("user_id")
+
+  page Page @relation(fields: [pageId], references: [id], onDelete: Cascade)
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@id([pageId, userId])
+  @@index([userId])
+  @@map("page_mentions")
+}
+
 model PagePendingContributor {
   pageId String @map("page_id")
   userId String @map("user_id")
@@ -439,6 +565,22 @@ model PageLabel {
   @@map("page_labels")
 }
 
+/// Personal page favorites (issue #132) — per user, deliberately NOT
+/// pond-wide (planning pivot documented on the issue). Trashed pages keep
+/// their rows, so a restore keeps the star; a purge cascades them away.
+model PageFavorite {
+  userId    String   @map("user_id")
+  pageId    String   @map("page_id")
+  createdAt DateTime @default(now()) @map("created_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+  page Page @relation(fields: [pageId], references: [id], onDelete: Cascade)
+
+  @@id([userId, pageId])
+  @@index([pageId])
+  @@map("page_favorites")
+}
+
 enum QuotaSubjectType {
   USER
   POND
@@ -478,15 +620,18 @@ model PondUsage {
 /// `<uploadsDir>/<pondId>/<id>` (FileStorageService); this row carries the
 /// metadata needed to serve and account for it. `pageId` starts unset —
 /// images are uploaded before the page referencing them is known
-/// (paste-then-insert, issue #28) — and is set on every page state save to
-/// whichever page's document currently embeds the file (issue #31,
-/// `PagesService.saveState`); the trash-purge job uses that link to delete
-/// a purged page's files. Not touched when an image is later removed from
-/// its page's content — an orphan-file sweep to reclaim those is a
-/// separate future maintenance job (operations.md), not this one.
-/// `deletedAt` stays unused for now — purge hard-deletes attachments
-/// directly rather than soft-deleting them first — reserved for that same
-/// future orphan-sweep job.
+/// (paste-then-insert, issue #28) — and is claimed on every collab persist
+/// by whichever page's document embeds the file (issue #31), or at upload
+/// for the page attachments panel (#61); the trash-purge job uses that
+/// link to delete a purged page's files. A row whose `pageId` is STILL
+/// null after a grace period was claimed by nothing and is reclaimed by
+/// the nightly orphan-file sweep (issue #194, OrphanSweepService).
+/// Claimed files are deliberately NOT auto-reclaimed when the content
+/// stops referencing them: the page attachments panel lists them as
+/// user-managed objects (insert is optional there), so "not embedded" is
+/// not "unused" — the pond file manager is the human cleanup path.
+/// Deletion is hard everywhere (sweep, purge, manual) — there is no
+/// soft-delete state on attachments (issue #194 removed `deletedAt`).
 model Attachment {
   id          String   @id @default(uuid())
   pondId      String   @map("pond_id")
@@ -496,8 +641,12 @@ model Attachment {
   sizeBytes   Int      @map("size_bytes")
   storagePath String   @map("storage_path")
   uploadedBy  String   @map("uploaded_by")
+  /// SHA-256 (hex) of the stored bytes (issue #199), computed from the
+  /// in-memory upload buffer as it is written — never by re-reading disk.
+  /// Downloads verify against it and fail closed on mismatch. Null only
+  /// for rows that predate #199 until the nightly backfill hashes them.
+  sha256      String?
   createdAt   DateTime @default(now()) @map("created_at")
-  deletedAt   DateTime? @map("deleted_at")
 
   pond     Pond  @relation(fields: [pondId], references: [id])
   page     Page? @relation(fields: [pageId], references: [id])
@@ -565,6 +714,53 @@ model AuthToken {
   @@map("auth_tokens")
 }
 
+enum ApiTokenScope {
+  READ
+  WRITE
+}
+
+/// Personal access tokens for the public API (issue #104). Only the SHA-256
+/// hash of the secret is stored (auth-tokens pattern); a token acts AS its
+/// user — the whole permission model applies — narrowed by `scope` and the
+/// optional pond restriction. Revoking keeps the row so the settings UI can
+/// show history; validation skips revoked/expired rows.
+/// Read-only feed authentication (issue #149): a `dt_feed_…` secret carried as
+/// a query parameter in Atom feed URLs, so feed readers can subscribe to
+/// non-public ponds/pages. Deliberately much narrower than an ApiToken —
+/// it can only ever authenticate the two feed endpoints, never the API.
+model FeedToken {
+  id         String    @id @default(uuid())
+  tokenHash  String    @unique @map("token_hash")
+  userId     String    @map("user_id")
+  name       String
+  lastUsedAt DateTime? @map("last_used_at")
+  createdAt  DateTime  @default(now()) @map("created_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@index([userId])
+  @@map("feed_tokens")
+}
+
+model ApiToken {
+  id         String        @id @default(uuid())
+  tokenHash  String        @unique @map("token_hash")
+  userId     String        @map("user_id")
+  name       String
+  scope      ApiTokenScope
+  /// Empty = every pond the user may access; else only these pond ids.
+  pondIds    String[]      @default([]) @map("pond_ids")
+  expiresAt  DateTime?     @map("expires_at")
+  revokedAt  DateTime?     @map("revoked_at")
+  lastUsedAt DateTime?     @map("last_used_at")
+  createdAt  DateTime      @default(now()) @map("created_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@index([userId])
+  @@map("api_tokens")
+}
+
 /// Fixed-window rate-limit counters (ADR 0002: no Redis). `key` encodes
 /// scope and subject, e.g. "login:ip:203.0.113.7".
 model RateLimit {
@@ -642,9 +838,11 @@ enum ConversionJobStatus {
 /// enqueued PENDING, a worker claims it (`FOR UPDATE SKIP LOCKED`, `lockedAt`
 /// recovers a crashed run), calls the pandoc sidecar with a timeout, and
 /// stores the output bytes or an `errorCode`. `input`/`result` are the raw
-/// document bytes — kept small by the request size limit and pruned by a
-/// later maintenance job (they are transient, not the durable copy an
-/// Attachment is). The polling endpoint `GET /jobs/:id` is owner-scoped.
+/// document bytes — kept small by the request size limit and transient, not
+/// the durable copy an Attachment is: the daily `conversion-payload-prune`
+/// job (#233) nulls both once a finished job passes
+/// `conversion.payloadRetentionDays`; the row survives for status/audit.
+/// The polling endpoint `GET /jobs/:id` is owner-scoped.
 model ConversionJob {
   id             String              @id @default(uuid())
   ownerId        String              @map("owner_id")
@@ -654,7 +852,9 @@ model ConversionJob {
   sourceFormat   String              @map("source_format")
   targetFormat   String              @map("target_format")
   standalone     Boolean             @default(true)
-  input          Bytes
+  /// Null once the retention job (#233) pruned a finished job's payload —
+  /// never while the job is PENDING/RUNNING (incl. stale-lock recovery).
+  input          Bytes?
   status         ConversionJobStatus @default(PENDING)
   attempts       Int                 @default(0)
   result         Bytes?
@@ -663,8 +863,12 @@ model ConversionJob {
   lockedAt       DateTime?           @map("locked_at")
   /// For a data-export job (#68): when its stored result stops being
   /// downloadable and is purged (GDPR data minimization). Null for every
-  /// other job kind, whose result never expires.
+  /// other job kind, whose payload the general retention (#233) prunes.
   expiresAt      DateTime?           @map("expires_at")
+  /// Kind-specific job options (issue #117): a vault import carries
+  /// `{parentPageId, labelIds, frontmatterMode}`; a PDF/DOCX/ODT export of a
+  /// classified page carries `{marking}` (issues #208/#209). Null otherwise.
+  options        Json?
   createdAt      DateTime            @default(now()) @map("created_at")
   updatedAt      DateTime            @updatedAt @map("updated_at")
 
@@ -706,6 +910,8 @@ model Plugin {
   mode        PluginInstanceMode @default(DISABLED)
   /// The full manifest as validated at install time (@dorfteich/plugin-sdk).
   manifest    Json
+  /// SHA-256 (hex) of the installed bundle ZIP (#232); null = pre-#232 install.
+  bundleHash  String?            @map("bundle_hash")
   installedAt DateTime           @default(now()) @map("installed_at")
   updatedAt   DateTime           @updatedAt @map("updated_at")
   /// Set when uninstalled; active queries filter `removedAt: null`.
@@ -732,3 +938,48 @@ model PondPlugin {
   @@id([pondId, pluginId])
   @@map("pond_plugins")
 }
+
+/// An operator-uploaded font family (issue #303, ADR 0016 §#303). The bytes
+/// live on disk under CUSTOM_FONTS_DIR — this row only records what the
+/// upload form stated, because the api never parses the font file itself.
+/// Additive to the compile-time catalog: a family whose name or slug
+/// collides with a catalog entry is rejected, so `fonts.<slot>.family` in a
+/// pond's settings stays unambiguous.
+model CustomFont {
+  id         String   @id @default(uuid())
+  /// CSS `font-family` name, as typed by the uploader.
+  family     String   @unique
+  /// URL/file-safe form; names the directory under CUSTOM_FONTS_DIR.
+  slug       String   @unique
+  /// Drives the system fallback stack, like FontCatalogEntry.category.
+  category   String
+  /// Free-text licence label, e.g. "Commercial — Foundry XY". Required so
+  /// an attribution obligation can be met on the font catalogue page.
+  licence    String
+  licenceUrl String?  @map("licence_url")
+  uploadedBy String   @map("uploaded_by")
+  createdAt  DateTime @default(now()) @map("created_at")
+  updatedAt  DateTime @updatedAt @map("updated_at")
+
+  uploader User               @relation(fields: [uploadedBy], references: [id])
+  weights  CustomFontWeight[]
+
+  @@map("custom_fonts")
+}
+
+/// One weight of a custom family. Style is always `normal`: the PDF
+/// `@font-face` builder emits only that, and browsers synthesise oblique —
+/// italic uploads are a follow-up, not a silent half-feature.
+model CustomFontWeight {
+  id       String  @id @default(uuid())
+  fontId   String  @map("font_id")
+  weight   Int
+  /// Whether a legacy WOFF was supplied next to the required WOFF2.
+  hasWoff  Boolean @default(false) @map("has_woff")
+  byteSize Int     @map("byte_size")
+
+  font CustomFont @relation(fields: [fontId], references: [id], onDelete: Cascade)
+
+  @@unique([fontId, weight])
+  @@map("custom_font_weights")
+}

apps/api/prisma/seed.ts

@@ -311,6 +311,36 @@ async function seedContentFixtures(ownerId: string): Promise<void> {
     deriveContentOf(everyElementDoc),
   );
 
+  // "Classified Note" (issue #206, ADR 0022): a VS-NfD-marked page so e2e
+  // (a11y pack) can assert the marking banner in both themes. Kept simple —
+  // the marking, not the content, is what the fixture exists for.
+  const classifiedDoc = editorSchema.node('doc', null, [
+    editorSchema.node('heading', { level: 1 }, [editorSchema.text('Classified Note')]),
+    editorSchema.node('paragraph', null, [
+      editorSchema.text('This fixture page carries the VS-NfD marking.'),
+    ]),
+  ]);
+  const classifiedYdoc = new Y.Doc();
+  prosemirrorJSONToYXmlFragment(
+    editorSchema,
+    classifiedDoc.toJSON(),
+    classifiedYdoc.getXmlFragment('default'),
+  );
+  const classifiedState = new Uint8Array(Y.encodeStateAsUpdate(classifiedYdoc));
+  classifiedYdoc.destroy();
+  const classifiedPageId = await upsertFixturePage(
+    pond.id,
+    'classified-note',
+    'Classified Note',
+    ownerId,
+    classifiedState,
+    deriveContentOf(classifiedDoc),
+  );
+  await prisma.page.update({
+    where: { id: classifiedPageId },
+    data: { classification: 'VS_NFD' },
+  });
+
   // "Fixture Image": one real, servable uploaded image (the Markdown
   // fixture above only carries a placeholder fileId for round-trip
   // testing — this is the one that actually resolves via /media/:fileId).

apps/api/scripts/gen-classified-reference-docs.mjs

@@ -0,0 +1,118 @@
+/**
+ * Regenerate the classified reference documents (issue #209, ADR 0022):
+ * `apps/api/assets/reference-vs-nfd.docx` / `.odt`.
+ *
+ * The DOCX/ODT export of a classified page passes these to pandoc via
+ * `--reference-doc`; pandoc copies the reference's page setup — including
+ * headers and footers — into its output, which is how the VS-NfD marking
+ * repeats on every page in Word and LibreOffice without being deletable
+ * body text.
+ *
+ * The binaries are DERIVED files: base = the default reference documents of
+ * the PINNED pandoc (`pandoc/core:3.6`, the exact sidecar the stages run),
+ * plus a header and footer carrying the marking. Never edit the binaries by
+ * hand — edit this script and re-run it (Docker required):
+ *
+ *   node apps/api/scripts/gen-classified-reference-docs.mjs
+ *
+ * The marking wording comes from @dorfteich/shared (single source, ADR
+ * 0022); the shared package must be built (`pnpm --filter @dorfteich/shared
+ * build`).
+ */
+import { execFileSync } from 'node:child_process';
+import { mkdirSync, writeFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { classificationMarking } from '@dorfteich/shared';
+import { strToU8, strFromU8, unzipSync, zipSync } from 'fflate';
+
+const PANDOC_IMAGE = 'pandoc/core:3.6';
+const MARKING = classificationMarking('vs_nfd');
+const outDir = join(dirname(fileURLToPath(import.meta.url)), '../assets');
+
+function defaultReference(name) {
+  return execFileSync('docker', ['run', '--rm', PANDOC_IMAGE, '--print-default-data-file', name], {
+    maxBuffer: 64 * 1024 * 1024,
+  });
+}
+
+function escapeXml(value) {
+  return value.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
+}
+
+/** DOCX: add word/header1.xml + word/footer1.xml, register them in the
+ * content types and document relationships, and reference them from the
+ * document's sectPr — Word repeats them on every page. */
+function patchDocx(bytes) {
+  const zip = unzipSync(new Uint8Array(bytes));
+  const marking = escapeXml(MARKING);
+
+  const partXml = (root) =>
+    `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>\n` +
+    `<w:${root} xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">` +
+    `<w:p><w:pPr><w:jc w:val="center"/></w:pPr>` +
+    `<w:r><w:rPr><w:b/></w:rPr><w:t xml:space="preserve">${marking}</w:t></w:r>` +
+    `</w:p></w:${root}>`;
+  zip['word/header1.xml'] = strToU8(partXml('hdr'));
+  zip['word/footer1.xml'] = strToU8(partXml('ftr'));
+
+  const types = strFromU8(zip['[Content_Types].xml']);
+  zip['[Content_Types].xml'] = strToU8(
+    types.replace(
+      '</Types>',
+      '<Override PartName="/word/header1.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.header+xml" />' +
+        '<Override PartName="/word/footer1.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.footer+xml" />' +
+        '</Types>',
+    ),
+  );
+
+  const rels = strFromU8(zip['word/_rels/document.xml.rels']);
+  zip['word/_rels/document.xml.rels'] = strToU8(
+    rels.replace(
+      '</Relationships>',
+      '<Relationship Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/header" Id="rIdVsNfdHeader" Target="header1.xml" />' +
+        '<Relationship Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/footer" Id="rIdVsNfdFooter" Target="footer1.xml" />' +
+        '</Relationships>',
+    ),
+  );
+
+  const doc = strFromU8(zip['word/document.xml']);
+  if (!doc.includes('<w:sectPr>')) throw new Error('reference.docx has no sectPr');
+  zip['word/document.xml'] = strToU8(
+    doc.replace(
+      '<w:sectPr>',
+      '<w:sectPr>' +
+        '<w:headerReference xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" w:type="default" r:id="rIdVsNfdHeader" />' +
+        '<w:footerReference xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" w:type="default" r:id="rIdVsNfdFooter" />',
+    ),
+  );
+
+  return zipSync(zip);
+}
+
+/** ODT: give the Standard master page a header with the marking and put the
+ * marking next to the existing page number in its footer — LibreOffice
+ * repeats master-page headers/footers on every page. */
+function patchOdt(bytes) {
+  const zip = unzipSync(new Uint8Array(bytes));
+  const marking = escapeXml(MARKING);
+  const styles = strFromU8(zip['styles.xml']);
+  if (!styles.includes('<style:footer>')) throw new Error('reference.odt has no footer');
+  const patched = styles
+    .replace(
+      '<style:footer>',
+      `<style:header><text:p text:style-name="MP1">${marking}</text:p></style:header><style:footer>`,
+    )
+    .replace(
+      '<style:footer>\n        <text:p text:style-name="MP1">',
+      `<style:footer>\n        <text:p text:style-name="MP1">${marking} · `,
+    );
+  zip['styles.xml'] = strToU8(patched);
+  return zipSync(zip);
+}
+
+mkdirSync(outDir, { recursive: true });
+writeFileSync(join(outDir, 'reference-vs-nfd.docx'), patchDocx(defaultReference('reference.docx')));
+writeFileSync(join(outDir, 'reference-vs-nfd.odt'), patchOdt(defaultReference('reference.odt')));
+console.log(`generated reference-vs-nfd.docx/.odt in ${outDir} (marking: ${MARKING})`);

apps/api/scripts/gen-default-favicon.mjs

@@ -0,0 +1,127 @@
+#!/usr/bin/env node
+/**
+ * Generates the shipped default favicons (issue #306):
+ * `apps/api/assets/default-favicon-32.png` and `-180.png`.
+ *
+ * The api serves these whenever an operator has not uploaded one, so an
+ * instance always has a tab icon — the `<link rel="icon">` in index.html is
+ * static and its resource must never 404.
+ *
+ * Drawn here rather than pulled in as a binary: the whole toolchain must
+ * survive the `--network none` offline build (96-offline-build-protokoll.md),
+ * and adding an image library for one 32×32 icon would be the tail wagging
+ * the dog. Node's own zlib is enough to write a PNG.
+ *
+ * Motif: a pond seen from above — the accent-green disc with two ripples.
+ *
+ * Regenerate with `node apps/api/scripts/gen-default-favicon.mjs`, commit
+ * script and binaries together.
+ */
+import { deflateSync } from 'node:zlib';
+import { writeFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+/** Brand green — the same value as index.html's light `theme-color`. */
+const GREEN = [0x2f, 0x6f, 0x4f];
+const LIGHT = [0xe8, 0xf2, 0xec];
+
+const crcTable = Array.from({ length: 256 }, (_, n) => {
+  let c = n;
+  for (let k = 0; k < 8; k += 1) c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
+  return c >>> 0;
+});
+
+function crc32(buf) {
+  let c = 0xffffffff;
+  for (const byte of buf) c = crcTable[(c ^ byte) & 0xff] ^ (c >>> 8);
+  return (c ^ 0xffffffff) >>> 0;
+}
+
+function chunk(type, data) {
+  const length = Buffer.alloc(4);
+  length.writeUInt32BE(data.length);
+  const body = Buffer.concat([Buffer.from(type, 'ascii'), data]);
+  const crc = Buffer.alloc(4);
+  crc.writeUInt32BE(crc32(body));
+  return Buffer.concat([length, body, crc]);
+}
+
+/** Minimal RGBA PNG writer — no filtering, one IDAT. */
+function encodePng(size, rgba) {
+  const ihdr = Buffer.alloc(13);
+  ihdr.writeUInt32BE(size, 0);
+  ihdr.writeUInt32BE(size, 4);
+  ihdr[8] = 8; // bit depth
+  ihdr[9] = 6; // colour type RGBA
+  const raw = Buffer.alloc(size * (size * 4 + 1));
+  for (let y = 0; y < size; y += 1) {
+    raw[y * (size * 4 + 1)] = 0; // filter: none
+    rgba.copy(raw, y * (size * 4 + 1) + 1, y * size * 4, (y + 1) * size * 4);
+  }
+  return Buffer.concat([
+    Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]),
+    chunk('IHDR', ihdr),
+    chunk('IDAT', deflateSync(raw, { level: 9 })),
+    chunk('IEND', Buffer.alloc(0)),
+  ]);
+}
+
+/**
+ * Colour at one point of the unit square, in continuous coordinates — the
+ * caller supersamples it, which is where the anti-aliasing comes from.
+ */
+function sample(x, y) {
+  const dx = x - 0.5;
+  const dy = y - 0.5;
+  const r = Math.hypot(dx, dy);
+  if (r > 0.48) return null; // outside the disc: transparent
+  // Two ripples spreading from a point struck slightly above centre — rings
+  // rather than a bullseye, which is why the centre stays green and the
+  // spacing widens outward the way real ripples do.
+  const rr = Math.hypot(dx, dy + 0.06);
+  const onRing = (radius, width) => Math.abs(rr - radius) < width;
+  if (onRing(0.33, 0.028) || onRing(0.19, 0.026)) return LIGHT;
+  return GREEN;
+}
+
+function render(size) {
+  const SS = 4; // supersampling factor
+  const out = Buffer.alloc(size * size * 4);
+  for (let y = 0; y < size; y += 1) {
+    for (let x = 0; x < size; x += 1) {
+      let r = 0;
+      let g = 0;
+      let b = 0;
+      let a = 0;
+      for (let sy = 0; sy < SS; sy += 1) {
+        for (let sx = 0; sx < SS; sx += 1) {
+          const c = sample((x + (sx + 0.5) / SS) / size, (y + (sy + 0.5) / SS) / size);
+          if (c) {
+            r += c[0];
+            g += c[1];
+            b += c[2];
+            a += 255;
+          }
+        }
+      }
+      const n = SS * SS;
+      const covered = a / 255;
+      const i = (y * size + x) * 4;
+      // Premultiplied average of the covered samples only, so the edge fades
+      // in alpha rather than towards black.
+      out[i] = covered ? Math.round(r / covered) : 0;
+      out[i + 1] = covered ? Math.round(g / covered) : 0;
+      out[i + 2] = covered ? Math.round(b / covered) : 0;
+      out[i + 3] = Math.round(a / n);
+    }
+  }
+  return out;
+}
+
+const assets = join(dirname(fileURLToPath(import.meta.url)), '../assets');
+for (const size of [32, 180]) {
+  const file = join(assets, `default-favicon-${size}.png`);
+  writeFileSync(file, encodePng(size, render(size)));
+  console.log(`wrote ${file}`);
+}

apps/api/src/admin/admin.controller.ts

@@ -11,9 +11,17 @@ import {
 } from '../settings/instance-settings.service';
 import { SiteAdminGuard } from './site-admin.guard';
 
-// Lifecycle markers, not configuration: never editable through this
-// endpoint (the setup lock must be irreversible, issue #80).
-const INTERNAL_KEYS: ReadonlySet<InstanceSettingKey> = new Set(['setup.completedAt']);
+// Lifecycle markers and file-backed metadata, not configuration: never
+// editable through this endpoint. The setup lock must be irreversible
+// (issue #80), and the branding entries only describe bytes on disk
+// (issue #306) — writing one by hand would claim an asset that is not
+// there. Both have their own write paths.
+const INTERNAL_KEYS: ReadonlySet<InstanceSettingKey> = new Set([
+  'setup.completedAt',
+  'instance.logo',
+  'instance.logoDark',
+  'instance.favicon',
+]);
 
 // Partial update: any subset of the known settings, each validated by
 // its own schema inside the service (double validation is fine — this

apps/api/src/admin/admin.module.ts

@@ -1,11 +1,16 @@
 import { Module } from '@nestjs/common';
 
 import { AuthModule } from '../auth/auth.module';
+import { BackupModule } from '../backup/backup.module';
+import { PondsModule } from '../ponds/ponds.module';
 import { QuotasModule } from '../quotas/quotas.module';
 import { SchedulerModule } from '../scheduler/scheduler.module';
+import { SearchModule } from '../search/search.module';
 import { UsersModule } from '../users/users.module';
 
 import { AdminSettingsController } from './admin.controller';
+import { BackupAdminController } from './backup-admin.controller';
+import { BackupAdminService } from './backup-admin.service';
 import { PseudonymizationService } from './pseudonymization.service';
 import { QuotaAdminController } from './quota-admin.controller';
 import { SystemAdminController } from './system-admin.controller';
@@ -15,13 +20,28 @@ import { UserAdminController } from './user-admin.controller';
 import { UserAdminService } from './user-admin.service';
 
 @Module({
-  imports: [QuotasModule, UsersModule, AuthModule, SchedulerModule],
+  imports: [
+    QuotasModule,
+    UsersModule,
+    AuthModule,
+    SchedulerModule,
+    BackupModule,
+    SearchModule,
+    PondsModule,
+  ],
   controllers: [
     AdminSettingsController,
+    BackupAdminController,
     QuotaAdminController,
     SystemAdminController,
     UserAdminController,
   ],
-  providers: [QuotaAdminService, SystemAdminService, UserAdminService, PseudonymizationService],
+  providers: [
+    BackupAdminService,
+    QuotaAdminService,
+    SystemAdminService,
+    UserAdminService,
+    PseudonymizationService,
+  ],
 })
 export class AdminModule {}

apps/api/src/admin/backup-admin.controller.ts

@@ -0,0 +1,73 @@
+import { Body, Controller, Get, HttpCode, Post, Put, Req, UseGuards } from '@nestjs/common';
+import {
+  backupConnectionTestInputSchema,
+  backupRestoreInputSchema,
+  backupSettingsInputSchema,
+  type BackupConnectionTestInput,
+  type BackupConnectionTestResult,
+  type BackupRestoreInput,
+  type BackupSetsView,
+  type BackupSettingsInput,
+  type BackupSettingsView,
+} from '@dorfteich/shared';
+
+import { AuthedRequest } from '../auth/auth.guard';
+import { ZodValidationPipe } from '../common/zod-validation.pipe';
+import { SiteAdminGuard } from './site-admin.guard';
+import { BackupAdminService } from './backup-admin.service';
+
+/**
+ * Site-Admin backup management (issue #103): Nextcloud target settings with
+ * a live connection test, the manual backup trigger, and the in-app restore
+ * (both answer 202 — the sidecar executes, progress arrives through the
+ * status files surfaced on GET /admin/system/backup).
+ */
+@Controller('admin/system/backup')
+@UseGuards(SiteAdminGuard)
+export class BackupAdminController {
+  constructor(private readonly backup: BackupAdminService) {}
+
+  @Get('settings')
+  settings(): Promise<BackupSettingsView> {
+    return this.backup.settingsView();
+  }
+
+  @Put('settings')
+  saveSettings(
+    @Body(new ZodValidationPipe(backupSettingsInputSchema)) input: BackupSettingsInput,
+    @Req() request: AuthedRequest,
+  ): Promise<BackupSettingsView> {
+    return this.backup.saveSettings(input, request.user!);
+  }
+
+  @Post('nextcloud/test')
+  @HttpCode(200)
+  testConnection(
+    @Body(new ZodValidationPipe(backupConnectionTestInputSchema))
+    input: BackupConnectionTestInput,
+  ): Promise<BackupConnectionTestResult> {
+    return this.backup.testConnection(input);
+  }
+
+  @Get('sets')
+  sets(): Promise<BackupSetsView> {
+    return this.backup.sets();
+  }
+
+  @Post('run')
+  @HttpCode(202)
+  async run(@Req() request: AuthedRequest): Promise<{ requested: true }> {
+    await this.backup.requestRun(request.user!);
+    return { requested: true };
+  }
+
+  @Post('restore')
+  @HttpCode(202)
+  async restore(
+    @Body(new ZodValidationPipe(backupRestoreInputSchema)) input: BackupRestoreInput,
+    @Req() request: AuthedRequest,
+  ): Promise<{ requested: true }> {
+    await this.backup.requestRestore(input, request.user!);
+    return { requested: true };
+  }
+}

apps/api/src/admin/backup-admin.e2e.db.test.ts

@@ -0,0 +1,408 @@
+import { createServer, type Server } from 'node:http';
+import { mkdtempSync, readFileSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { setTimeout as sleep } from 'node:timers/promises';
+
+import { INestApplication } from '@nestjs/common';
+import {
+  BACKUP_COMMAND_CHANNEL,
+  RESTORE_STATUS_FILE,
+  archiveFileName,
+  dumpFileName,
+  type BackupCommand,
+  type BackupSetsView,
+  type BackupSettingsView,
+  type RestoreStatus,
+  type SystemBackupView,
+} from '@dorfteich/shared';
+import { PrismaClient } from '@prisma/client';
+import { Client } from 'pg';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * A fake Nextcloud endpoint covering the WebDAV subset the admin endpoints
+ * use (PROPFIND/MKCOL) plus a remote bundle listing — the connection test
+ * and the restore picker run against real HTTP.
+ */
+function createDavServer(): {
+  server: Server;
+  start(): Promise<string>;
+  stop(): Promise<void>;
+  setAuthOk(ok: boolean): void;
+} {
+  let authOk = true;
+  const files = ['dorfteich-backup-20260710-030000.tar.gz'];
+  const server = createServer((req, res) => {
+    if (!authOk) {
+      res.statusCode = 401;
+      return res.end();
+    }
+    if (req.method === 'PROPFIND') {
+      const depth = req.headers.depth;
+      res.statusCode = 207;
+      res.setHeader('Content-Type', 'application/xml');
+      const children =
+        depth === '1'
+          ? files
+              .map(
+                (name) => `<d:response><d:href>${req.url}/${name}</d:href><d:propstat><d:prop>
+                  <d:getcontentlength>2048</d:getcontentlength><d:resourcetype/>
+                </d:prop></d:propstat></d:response>`,
+              )
+              .join('')
+          : '';
+      return res.end(
+        `<?xml version="1.0"?><d:multistatus xmlns:d="DAV:">
+          <d:response><d:href>${req.url}/</d:href><d:propstat><d:prop>
+            <d:resourcetype><d:collection/></d:resourcetype>
+          </d:prop></d:propstat></d:response>${children}</d:multistatus>`,
+      );
+    }
+    if (req.method === 'MKCOL') {
+      res.statusCode = 201;
+      return res.end();
+    }
+    res.statusCode = 405;
+    res.end();
+  });
+  return {
+    server,
+    setAuthOk: (ok) => {
+      authOk = ok;
+    },
+    start: () =>
+      new Promise((resolve) => {
+        server.listen(0, '127.0.0.1', () => {
+          resolve(`http://127.0.0.1:${(server.address() as { port: number }).port}`);
+        });
+      }),
+    stop: () => new Promise((resolve) => server.close(() => resolve())),
+  };
+}
+
+/**
+ * Backup administration end to end (issue #103): settings roundtrip with
+ * the app password landing in the secret store (never the database), the
+ * live connection test, the restore picker's set listing, command NOTIFYs
+ * for run/restore, the public restore-status endpoint, and the maintenance
+ * gate's 503 semantics including staleness.
+ */
+describe.skipIf(!hasTestDb)('backup admin (e2e, issue #103)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  let backupsDir: string;
+  let secretsFile: string;
+  let davUrl: string;
+  const dav = createDavServer();
+  const suffix = uniqueSuffix();
+  const password = 'backupadmin ist vorsichtig 1';
+  const ids: Record<string, string> = {};
+  const cookies: Record<string, string> = {};
+  const baseSecretsFile = process.env.SECRETS_FILE;
+
+  const commands: BackupCommand[] = [];
+  let listenClient: Client;
+
+  const api = () => request(app.getHttpServer());
+
+  async function makeUser(handle: string, siteAdmin: boolean): Promise<void> {
+    const users = app.get(UsersService);
+    const username = `bak-${handle}-${suffix}`;
+    const user = await users.createUser({
+      username,
+      email: `${username}@example.org`,
+      displayName: `Bak ${handle}`,
+      password,
+      locale: 'en',
+    });
+    await users.markEmailVerified(user.id);
+    if (siteAdmin)
+      await prisma.user.update({ where: { id: user.id }, data: { isSiteAdmin: true } });
+    ids[handle] = user.id;
+    cookies[handle] = sessionCookieOf(
+      await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: username, password })
+        .expect(200),
+    );
+  }
+
+  function settingsInput(overrides: Record<string, unknown> = {}): Record<string, unknown> {
+    return {
+      localRetentionDays: 14,
+      remoteRetentionDays: 60,
+      nextcloud: {
+        enabled: true,
+        baseUrl: davUrl,
+        username: 'clouduser',
+        folder: `dorfteich-e2e-${suffix}`,
+        uploadSchedule: 'weekly',
+        password: 'app-password-123',
+        ...((overrides.nextcloud as object) ?? {}),
+      },
+      ...Object.fromEntries(Object.entries(overrides).filter(([k]) => k !== 'nextcloud')),
+    };
+  }
+
+  beforeAll(async () => {
+    backupsDir = mkdtempSync(join(tmpdir(), 'dorfteich-backup-admin-'));
+    secretsFile = join(mkdtempSync(join(tmpdir(), 'dorfteich-backup-secrets-')), 'secrets.env');
+    process.env.BACKUPS_DIR = backupsDir;
+    process.env.SECRETS_FILE = secretsFile;
+    // The in-test WebDAV server must be allowlisted (issue #192) — the
+    // policy paths themselves are covered by backup-allowlist*.e2e.db.test.ts.
+    process.env.BACKUP_ALLOWED_TARGETS = '127.0.0.1';
+    davUrl = await dav.start();
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    // Clean leftovers of earlier runs — the settings keys are singletons.
+    await prisma.instanceSetting.deleteMany({ where: { key: { startsWith: 'backup.' } } });
+    app = await createTestApp();
+    await makeUser('admin', true);
+    await makeUser('user', false);
+
+    listenClient = new Client({ connectionString: process.env.TEST_DATABASE_URL });
+    await listenClient.connect();
+    listenClient.on('notification', (message) => {
+      if (message.channel === BACKUP_COMMAND_CHANNEL && message.payload) {
+        commands.push(JSON.parse(message.payload) as BackupCommand);
+      }
+    });
+    await listenClient.query(`LISTEN ${BACKUP_COMMAND_CHANNEL}`);
+  });
+
+  afterAll(async () => {
+    delete process.env.BACKUPS_DIR;
+    if (baseSecretsFile === undefined) delete process.env.SECRETS_FILE;
+    else process.env.SECRETS_FILE = baseSecretsFile;
+    await dav.stop();
+    await listenClient.end().catch(() => undefined);
+    const all = Object.values(ids);
+    await prisma.instanceSetting.deleteMany({ where: { key: { startsWith: 'backup.' } } });
+    await prisma.auditEntry.deleteMany({ where: { actorId: { in: all } } });
+    await prisma.session.deleteMany({ where: { userId: { in: all } } });
+    await prisma.userIdentity.deleteMany({ where: { userId: { in: all } } });
+    await prisma.user.deleteMany({ where: { id: { in: all } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('rejects non-admins on every backup admin route', async () => {
+    for (const [method, path] of [
+      ['get', '/api/v1/admin/system/backup/settings'],
+      ['put', '/api/v1/admin/system/backup/settings'],
+      ['post', '/api/v1/admin/system/backup/nextcloud/test'],
+      ['get', '/api/v1/admin/system/backup/sets'],
+      ['post', '/api/v1/admin/system/backup/run'],
+      ['post', '/api/v1/admin/system/backup/restore'],
+    ] as const) {
+      await api()[method](path).set('Cookie', cookies.user!).expect(403);
+    }
+  });
+
+  it('tests the connection against a live WebDAV endpoint', async () => {
+    const ok = await api()
+      .post('/api/v1/admin/system/backup/nextcloud/test')
+      .set('Cookie', cookies.admin!)
+      .send({
+        baseUrl: davUrl,
+        username: 'clouduser',
+        folder: 'dorfteich-e2e',
+        password: 'app-password-123',
+      })
+      .expect(200);
+    expect(ok.body).toEqual({ ok: true });
+
+    dav.setAuthOk(false);
+    const bad = await api()
+      .post('/api/v1/admin/system/backup/nextcloud/test')
+      .set('Cookie', cookies.admin!)
+      .send({
+        baseUrl: davUrl,
+        username: 'clouduser',
+        folder: 'dorfteich-e2e',
+        password: 'wrong',
+      })
+      .expect(200);
+    expect(bad.body.ok).toBe(false);
+    expect(String(bad.body.error)).toContain('authentication failed');
+    dav.setAuthOk(true);
+  });
+
+  it('refuses to save an enabled target that fails the connection test', async () => {
+    dav.setAuthOk(false);
+    const res = await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', cookies.admin!)
+      .send(settingsInput())
+      .expect(400);
+    expect(res.body.code).toBe('backup_connection_failed');
+    dav.setAuthOk(true);
+    // Nothing was persisted.
+    const view = await api()
+      .get('/api/v1/admin/system/backup/settings')
+      .set('Cookie', cookies.admin!)
+      .expect(200);
+    expect((view.body as BackupSettingsView).nextcloud.enabled).toBe(false);
+  });
+
+  it('saves settings, keeping the app password out of the database', async () => {
+    const res = await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', cookies.admin!)
+      .send(settingsInput())
+      .expect(200);
+    const view = res.body as BackupSettingsView;
+    expect(view).toMatchObject({
+      localRetentionDays: 14,
+      remoteRetentionDays: 60,
+      nextcloud: {
+        enabled: true,
+        baseUrl: davUrl,
+        username: 'clouduser',
+        uploadSchedule: 'weekly',
+        passwordSet: true,
+      },
+    });
+
+    // Secret store holds the password; instance_settings never does.
+    expect(readFileSync(secretsFile, 'utf8')).toMatch(
+      /BACKUP_NEXTCLOUD_PASSWORD="?app-password-123"?/,
+    );
+    const rows = await prisma.instanceSetting.findMany({
+      where: { key: { startsWith: 'backup.' } },
+    });
+    expect(JSON.stringify(rows.map((row) => row.value))).not.toContain('app-password-123');
+
+    // Re-saving without a password keeps the stored one (write-only field).
+    await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', cookies.admin!)
+      .send(settingsInput({ nextcloud: { password: undefined } }))
+      .expect(200);
+    expect(readFileSync(secretsFile, 'utf8')).toMatch(
+      /BACKUP_NEXTCLOUD_PASSWORD="?app-password-123"?/,
+    );
+  });
+
+  it('lists local and remote restore sets, and reflects the target on the card', async () => {
+    writeFileSync(join(backupsDir, dumpFileName('20260712-030000')), 'dump');
+    writeFileSync(join(backupsDir, archiveFileName('20260712-030000')), 'archive');
+    // An incomplete set never shows up as restorable.
+    writeFileSync(join(backupsDir, dumpFileName('20260712-040000')), 'dump-only');
+
+    const res = await api()
+      .get('/api/v1/admin/system/backup/sets')
+      .set('Cookie', cookies.admin!)
+      .expect(200);
+    const sets = res.body as BackupSetsView;
+    expect(sets.remoteConfigured).toBe(true);
+    expect(sets.local.map((s) => s.backupId)).toEqual(['20260712-030000']);
+    expect(sets.remote.map((s) => s.backupId)).toEqual(['20260710-030000']);
+    expect(sets.remote[0]!.sizeBytes).toBe(2048);
+
+    const card = await api()
+      .get('/api/v1/admin/system/backup')
+      .set('Cookie', cookies.admin!)
+      .expect(200);
+    expect((card.body as SystemBackupView).remoteConfigured).toBe(true);
+  });
+
+  it('sends run and restore commands over NOTIFY, audit-logged', async () => {
+    commands.length = 0;
+    await api().post('/api/v1/admin/system/backup/run').set('Cookie', cookies.admin!).expect(202);
+
+    await api()
+      .post('/api/v1/admin/system/backup/restore')
+      .set('Cookie', cookies.admin!)
+      .send({ source: 'local', backupId: '20260712-030000', confirm: '20260712-030000' })
+      .expect(202);
+
+    await sleep(300);
+    expect(commands).toEqual([
+      { kind: 'run', requestedBy: `bak-admin-${suffix}` },
+      {
+        kind: 'restore',
+        source: 'local',
+        backupId: '20260712-030000',
+        requestedBy: `bak-admin-${suffix}`,
+      },
+    ]);
+
+    const audit = await prisma.auditEntry.findMany({
+      where: { actorId: ids.admin!, action: { startsWith: 'backup.' } },
+    });
+    const actions = audit.map((entry) => entry.action);
+    expect(actions).toContain('backup.run_triggered');
+    expect(actions).toContain('backup.restore_requested');
+  });
+
+  it('guards the restore trigger: confirm mismatch, unknown sets, bad sources', async () => {
+    await api()
+      .post('/api/v1/admin/system/backup/restore')
+      .set('Cookie', cookies.admin!)
+      .send({ source: 'local', backupId: '20260712-030000', confirm: 'nope' })
+      .expect(400);
+
+    await api()
+      .post('/api/v1/admin/system/backup/restore')
+      .set('Cookie', cookies.admin!)
+      .send({ source: 'local', backupId: '20260712-040000', confirm: '20260712-040000' })
+      .expect(404);
+
+    await api()
+      .post('/api/v1/admin/system/backup/restore')
+      .set('Cookie', cookies.admin!)
+      .send({ source: 'remote', backupId: '20260712-050000', confirm: '20260712-050000' })
+      .expect(404);
+  });
+
+  it('serves the public restore status and gates the api during a restore', async () => {
+    // No restore yet → idle, and the api serves normally.
+    const idle = await api().get('/api/v1/backup/restore-status').expect(200);
+    expect(idle.body).toEqual({ state: 'idle' });
+
+    const running: RestoreStatus = {
+      schemaVersion: 1,
+      state: 'running',
+      backupId: '20260712-030000',
+      source: 'local',
+      requestedBy: 'admin',
+      startedAt: new Date().toISOString(),
+      finishedAt: null,
+    };
+    writeFileSync(join(backupsDir, RESTORE_STATUS_FILE), JSON.stringify(running));
+    await sleep(1600); // maintenance state cache TTL
+
+    // Anonymous status endpoint keeps answering; everything else 503s.
+    const status = await api().get('/api/v1/backup/restore-status').expect(200);
+    expect((status.body as RestoreStatus).state).toBe('running');
+    const gated = await api().get('/api/v1/ponds').set('Cookie', cookies.admin!).expect(503);
+    expect(gated.body.code).toBe('maintenance_mode');
+    await api().get('/api/v1/healthz').expect(200);
+
+    // A crashed restore (stale running state) must not brick the instance.
+    writeFileSync(
+      join(backupsDir, RESTORE_STATUS_FILE),
+      JSON.stringify({ ...running, startedAt: new Date(Date.now() - 31 * 60_000).toISOString() }),
+    );
+    await sleep(1600);
+    await api().get('/api/v1/ponds').set('Cookie', cookies.admin!).expect(200);
+
+    // A finished restore leaves the gate open and reports its result.
+    writeFileSync(
+      join(backupsDir, RESTORE_STATUS_FILE),
+      JSON.stringify({ ...running, state: 'succeeded', finishedAt: new Date().toISOString() }),
+    );
+    await sleep(1600);
+    const done = await api().get('/api/v1/backup/restore-status').expect(200);
+    expect((done.body as RestoreStatus).state).toBe('succeeded');
+    await api().get('/api/v1/ponds').set('Cookie', cookies.admin!).expect(200);
+  });
+});

apps/api/src/admin/backup-admin.service.ts

@@ -0,0 +1,226 @@
+import { readdirSync } from 'node:fs';
+import { statSync } from 'node:fs';
+import { join } from 'node:path';
+
+import {
+  BadRequestException,
+  ConflictException,
+  Injectable,
+  NotFoundException,
+} from '@nestjs/common';
+import {
+  BACKUP_COMMAND_CHANNEL,
+  archiveFileName,
+  backupIdTime,
+  dumpFileName,
+  listSets,
+  remoteBundleId,
+  type BackupCommand,
+  type BackupConnectionTestInput,
+  type BackupConnectionTestResult,
+  type BackupRestoreInput,
+  type BackupSetView,
+  type BackupSetsView,
+  type BackupSettingsInput,
+  type BackupSettingsView,
+} from '@dorfteich/shared';
+import { webdavList } from '@dorfteich/shared/webdav';
+import { User } from '@prisma/client';
+
+import { AuditService } from '../audit/audit.service';
+import { BackupTargetService } from '../backup/backup-target.service';
+import { MaintenanceStateService } from '../backup/maintenance-state.service';
+import { AppConfig } from '../config/app-config.service';
+import { PrismaService } from '../prisma/prisma.service';
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+
+/**
+ * Site-Admin backup management (issue #103): the Nextcloud target
+ * configuration, manual "back up now", the restore picker (local sets from
+ * the read-only backups mount, remote sets via WebDAV), and the restore
+ * trigger. The sidecar does the actual work — commands travel over the
+ * {@link BACKUP_COMMAND_CHANNEL} NOTIFY bus, progress comes back through
+ * `status.json`/`restore-status.json`.
+ */
+@Injectable()
+export class BackupAdminService {
+  constructor(
+    private readonly target: BackupTargetService,
+    private readonly maintenance: MaintenanceStateService,
+    private readonly settings: InstanceSettingsService,
+    private readonly prisma: PrismaService,
+    private readonly audit: AuditService,
+    private readonly config: AppConfig,
+  ) {}
+
+  settingsView(): Promise<BackupSettingsView> {
+    return this.target.settingsView();
+  }
+
+  /**
+   * Persists the backup settings. When the Nextcloud side is enabled, the
+   * connection is live-tested first (with the new password if provided,
+   * else the stored one) — like the setup wizard's SMTP step, nothing is
+   * saved on failure.
+   */
+  async saveSettings(input: BackupSettingsInput, actor: User): Promise<BackupSettingsView> {
+    if (input.nextcloud.enabled) {
+      this.assertTargetAllowed(input.nextcloud.baseUrl);
+      const test = await this.target.testConnection({
+        baseUrl: input.nextcloud.baseUrl,
+        username: input.nextcloud.username,
+        folder: input.nextcloud.folder,
+        password: input.nextcloud.password,
+      });
+      if (!test.ok) {
+        throw new BadRequestException({
+          code: 'backup_connection_failed',
+          details: { nextcloud: [test.error ?? 'connection failed'] },
+        });
+      }
+    }
+    await this.target.storePassword(input.nextcloud.password ?? '');
+    await this.settings.set('backup.localRetentionDays', input.localRetentionDays, actor.id);
+    await this.settings.set('backup.remoteRetentionDays', input.remoteRetentionDays, actor.id);
+    await this.settings.set('backup.nextcloud.enabled', input.nextcloud.enabled, actor.id);
+    await this.settings.set('backup.nextcloud.baseUrl', input.nextcloud.baseUrl, actor.id);
+    await this.settings.set('backup.nextcloud.username', input.nextcloud.username, actor.id);
+    await this.settings.set('backup.nextcloud.folder', input.nextcloud.folder, actor.id);
+    await this.settings.set(
+      'backup.nextcloud.uploadSchedule',
+      input.nextcloud.uploadSchedule,
+      actor.id,
+    );
+    // settings.set audits each key; one summary entry names the intent.
+    await this.audit.record({
+      action: 'backup.settings_changed',
+      actorId: actor.id,
+      details: { nextcloudEnabled: input.nextcloud.enabled },
+    });
+    return this.settingsView();
+  }
+
+  testConnection(input: BackupConnectionTestInput): Promise<BackupConnectionTestResult> {
+    // Policy first (issue #192): the "test connection" button must not be
+    // usable as an egress probe towards non-allowlisted hosts.
+    this.assertTargetAllowed(input.baseUrl);
+    return this.target.testConnection(input);
+  }
+
+  /**
+   * Deploy-level target policy (issue #192, ADR 0026): an empty
+   * `BACKUP_ALLOWED_TARGETS` disables remote targets outright; a host
+   * outside the list is rejected with an admin-visible error.
+   */
+  private assertTargetAllowed(baseUrl: string): void {
+    if (!this.target.remoteAllowed()) {
+      throw new BadRequestException({ code: 'backup_remote_disabled_by_policy' });
+    }
+    if (!this.target.targetAllowed(baseUrl)) {
+      throw new BadRequestException({
+        code: 'backup_target_not_allowed',
+        details: { nextcloud: [`host is not in BACKUP_ALLOWED_TARGETS`] },
+      });
+    }
+  }
+
+  /** Both restore sources for the picker: newest first. */
+  async sets(): Promise<BackupSetsView> {
+    const local = this.localSets();
+    const target = await this.target.resolveTarget();
+    if (!target) return { local, remoteConfigured: false, remote: [] };
+
+    const listed = await webdavList(target);
+    if (!listed.ok) {
+      return { local, remoteConfigured: true, remote: [], remoteError: listed.error };
+    }
+    const remote = listed.value
+      .filter((entry) => !entry.isCollection)
+      .map((entry) => ({ id: remoteBundleId(entry.name), sizeBytes: entry.sizeBytes }))
+      .filter((entry): entry is { id: string; sizeBytes: number | null } => entry.id !== null)
+      .map((entry) => this.setView(entry.id, entry.sizeBytes))
+      .sort((a, b) => b.backupId.localeCompare(a.backupId));
+    return { local, remoteConfigured: true, remote };
+  }
+
+  /** "Back up now": dump + upload, executed by the sidecar (202-style). */
+  async requestRun(actor: User): Promise<void> {
+    await this.notify({ kind: 'run', requestedBy: actor.username });
+    await this.audit.record({ action: 'backup.run_triggered', actorId: actor.id });
+  }
+
+  /**
+   * Requests an in-app restore. The type-to-confirm value must repeat the
+   * backup id — the UI enforces it too, this is the server-side backstop
+   * for the most destructive action the instance has.
+   */
+  async requestRestore(input: BackupRestoreInput, actor: User): Promise<void> {
+    if (input.confirm !== input.backupId) {
+      throw new BadRequestException({ code: 'backup_restore_confirm_mismatch' });
+    }
+    if (this.maintenance.current()?.state === 'running' && this.maintenance.isActive()) {
+      throw new ConflictException({ code: 'backup_restore_running' });
+    }
+    if (input.source === 'remote') {
+      const target = await this.target.resolveTarget();
+      if (!target) throw new BadRequestException({ code: 'backup_remote_not_configured' });
+      const listed = await webdavList(target);
+      const exists =
+        listed.ok && listed.value.some((entry) => remoteBundleId(entry.name) === input.backupId);
+      if (!exists) throw new NotFoundException({ code: 'backup_set_not_found' });
+    } else {
+      const complete = this.localSets().some((set) => set.backupId === input.backupId);
+      if (!complete) throw new NotFoundException({ code: 'backup_set_not_found' });
+    }
+    await this.notify({
+      kind: 'restore',
+      source: input.source,
+      backupId: input.backupId,
+      requestedBy: actor.username,
+    });
+    await this.audit.record({
+      action: 'backup.restore_requested',
+      actorId: actor.id,
+      targetType: 'backup',
+      targetId: input.backupId,
+      details: { source: input.source },
+    });
+  }
+
+  private async notify(command: BackupCommand): Promise<void> {
+    await this.prisma
+      .$executeRaw`SELECT pg_notify(${BACKUP_COMMAND_CHANNEL}, ${JSON.stringify(command)})`;
+  }
+
+  /** Complete sets on the read-only backups mount, newest first. */
+  private localSets(): BackupSetView[] {
+    let names: string[];
+    try {
+      names = readdirSync(this.config.env.BACKUPS_DIR);
+    } catch {
+      return [];
+    }
+    return listSets(names)
+      .filter((set) => set.complete)
+      .map((set) => {
+        let sizeBytes: number | null = 0;
+        for (const file of [dumpFileName(set.id), archiveFileName(set.id)]) {
+          try {
+            sizeBytes = (sizeBytes ?? 0) + statSync(join(this.config.env.BACKUPS_DIR, file)).size;
+          } catch {
+            sizeBytes = null;
+          }
+        }
+        return this.setView(set.id, sizeBytes);
+      })
+      .sort((a, b) => b.backupId.localeCompare(a.backupId));
+  }
+
+  private setView(backupId: string, sizeBytes: number | null): BackupSetView {
+    return {
+      backupId,
+      startedAt: backupIdTime(backupId)?.toISOString() ?? new Date(0).toISOString(),
+      sizeBytes,
+    };
+  }
+}

apps/api/src/admin/backup-allowlist-empty.e2e.db.test.ts

@@ -0,0 +1,101 @@
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * Backup target allowlist (issue #192, ADR 0026), empty-list half: with
+ * `BACKUP_ALLOWED_TARGETS` unset (the default) every remote target is
+ * unavailable by policy — the view says so, and enabling one is rejected
+ * before any connection attempt. Lives in its own file because the env is
+ * read once at app boot.
+ */
+describe.skipIf(!hasTestDb)('backup targets disabled by empty allowlist (e2e, issue #192)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const password = 'backup allowlist pass 2';
+  let adminId: string;
+  let adminCookie: string;
+
+  const api = () => request(app.getHttpServer());
+
+  beforeAll(async () => {
+    delete process.env.BACKUP_ALLOWED_TARGETS;
+    prisma = createTestPrisma();
+    app = await createTestApp();
+    const users = app.get(UsersService);
+    const username = `bae-admin-${suffix}`;
+    const admin = await users.createUser({
+      username,
+      email: `${username}@example.org`,
+      displayName: 'Backup Admin Empty',
+      password,
+      locale: 'en',
+    });
+    adminId = admin.id;
+    await users.markEmailVerified(adminId);
+    await prisma.user.update({ where: { id: adminId }, data: { isSiteAdmin: true } });
+    adminCookie = sessionCookieOf(
+      await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: username, password })
+        .expect(200),
+    );
+  });
+
+  afterAll(async () => {
+    await prisma.auditEntry.deleteMany({ where: { actorId: adminId } });
+    await prisma.session.deleteMany({ where: { userId: adminId } });
+    await prisma.userIdentity.deleteMany({ where: { userId: adminId } });
+    await prisma.user.deleteMany({ where: { id: adminId } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('reports remote targets as unavailable by policy', async () => {
+    const res = await api()
+      .get('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .expect(200);
+    expect(res.body.remoteTargets).toEqual({ allowed: false, allowlist: [] });
+  });
+
+  it('rejects enabling any remote destination', async () => {
+    const res = await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .send({
+        localRetentionDays: null,
+        remoteRetentionDays: 30,
+        nextcloud: {
+          enabled: true,
+          baseUrl: 'https://cloud.example.org/dav',
+          username: 'backupuser',
+          folder: 'dorfteich-backups',
+          uploadSchedule: 'daily',
+          password: 'app-pass',
+        },
+      })
+      .expect(400);
+    expect(res.body.code).toBe('backup_remote_disabled_by_policy');
+  });
+
+  it('rejects the connection test outright', async () => {
+    const res = await api()
+      .post('/api/v1/admin/system/backup/nextcloud/test')
+      .set('Cookie', adminCookie)
+      .send({
+        baseUrl: 'https://cloud.example.org/dav',
+        username: 'backupuser',
+        folder: 'dorfteich-backups',
+        password: 'app-pass',
+      })
+      .expect(400);
+    expect(res.body.code).toBe('backup_remote_disabled_by_policy');
+  });
+});

apps/api/src/admin/backup-allowlist.e2e.db.test.ts

@@ -0,0 +1,134 @@
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+// Deploy-level env — must be set BEFORE the app (AppConfig) boots.
+process.env.BACKUP_ALLOWED_TARGETS = 'cloud.example.org';
+
+/**
+ * Backup target allowlist (issue #192, ADR 0026), populated-list half:
+ * hosts outside `BACKUP_ALLOWED_TARGETS` are rejected admin-visibly, hosts
+ * inside pass the policy. The empty-list half lives in its own file
+ * (`backup-allowlist-empty.e2e.db.test.ts`) because the env is read once
+ * at app boot.
+ */
+describe.skipIf(!hasTestDb)('backup target allowlist (e2e, issue #192)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const password = 'backup allowlist pass 1';
+  let adminId: string;
+  let adminCookie: string;
+
+  const api = () => request(app.getHttpServer());
+
+  const settingsInput = (baseUrl: string, enabled = true) => ({
+    localRetentionDays: null,
+    remoteRetentionDays: 30,
+    nextcloud: {
+      enabled,
+      baseUrl,
+      username: 'backupuser',
+      folder: 'dorfteich-backups',
+      uploadSchedule: 'daily',
+      password: 'app-pass',
+    },
+  });
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    app = await createTestApp();
+    const users = app.get(UsersService);
+    const username = `bal-admin-${suffix}`;
+    const admin = await users.createUser({
+      username,
+      email: `${username}@example.org`,
+      displayName: 'Backup Admin',
+      password,
+      locale: 'en',
+    });
+    adminId = admin.id;
+    await users.markEmailVerified(adminId);
+    await prisma.user.update({ where: { id: adminId }, data: { isSiteAdmin: true } });
+    adminCookie = sessionCookieOf(
+      await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: username, password })
+        .expect(200),
+    );
+  });
+
+  afterAll(async () => {
+    await prisma.instanceSetting.deleteMany({ where: { key: { startsWith: 'backup.' } } });
+    await prisma.auditEntry.deleteMany({ where: { actorId: adminId } });
+    await prisma.session.deleteMany({ where: { userId: adminId } });
+    await prisma.userIdentity.deleteMany({ where: { userId: adminId } });
+    await prisma.user.deleteMany({ where: { id: adminId } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('exposes the policy in the settings view', async () => {
+    const res = await api()
+      .get('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .expect(200);
+    expect(res.body.remoteTargets).toEqual({
+      allowed: true,
+      allowlist: ['cloud.example.org'],
+    });
+  });
+
+  it('rejects enabling a destination outside the allowlist', async () => {
+    const res = await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .send(settingsInput('https://evil.example.net/dav'))
+      .expect(400);
+    expect(res.body.code).toBe('backup_target_not_allowed');
+  });
+
+  it('rejects the connection test towards a non-allowlisted host', async () => {
+    const res = await api()
+      .post('/api/v1/admin/system/backup/nextcloud/test')
+      .set('Cookie', adminCookie)
+      .send({
+        baseUrl: 'https://evil.example.net/dav',
+        username: 'backupuser',
+        folder: 'dorfteich-backups',
+        password: 'app-pass',
+      })
+      .expect(400);
+    expect(res.body.code).toBe('backup_target_not_allowed');
+  });
+
+  it('lets an allowlisted destination through the policy', async () => {
+    // The host passes the policy; what fails afterwards is the live
+    // connection test against the (unreachable) example host — proving the
+    // rejection above was the policy, not the connectivity.
+    const res = await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .send(settingsInput('https://cloud.example.org/dav'))
+      .expect(400);
+    expect(res.body.code).toBe('backup_connection_failed');
+
+    // Saving the same destination disabled skips the connection test and
+    // persists — an existing in-allowlist configuration stays untouched.
+    await api()
+      .put('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .send(settingsInput('https://cloud.example.org/dav', false))
+      .expect(200);
+    const view = await api()
+      .get('/api/v1/admin/system/backup/settings')
+      .set('Cookie', adminCookie)
+      .expect(200);
+    expect(view.body.nextcloud.baseUrl).toBe('https://cloud.example.org/dav');
+  });
+});

apps/api/src/admin/pseudonymization.service.ts

@@ -4,6 +4,7 @@ import { PinoLogger } from 'nestjs-pino';
 
 import { AuditService } from '../audit/audit.service';
 import { PrismaService } from '../prisma/prisma.service';
+import { SearchProvider } from '../search/search.provider';
 
 /**
  * GDPR account deletion (issue #59, security.md §Privacy). Rather than
@@ -17,6 +18,7 @@ export class PseudonymizationService {
   constructor(
     private readonly prisma: PrismaService,
     private readonly audit: AuditService,
+    private readonly search: SearchProvider,
     private readonly logger: PinoLogger,
   ) {
     this.logger.setContext(PseudonymizationService.name);
@@ -45,6 +47,14 @@ export class PseudonymizationService {
         data: { deletedAt: new Date(), deletedBy: userId },
       });
     });
+    // Trash path includes leaving the search index (issue #195).
+    const personalPonds = await this.prisma.pond.findMany({
+      where: { ownerId: userId, type: 'PERSONAL' },
+      select: { id: true },
+    });
+    for (const pond of personalPonds) {
+      await this.search.removePond(pond.id);
+    }
     await this.audit.record({
       action: 'user.pseudonymized',
       targetType: 'user',

apps/api/src/admin/system-admin.controller.ts

@@ -1,16 +1,21 @@
 import { Controller, Get, Param, Post, Query, Req, UseGuards } from '@nestjs/common';
 import {
   auditListQuerySchema,
+  readEventListQuerySchema,
   type AuditListQuery,
   type AuditListView,
   type JobTriggerResult,
+  type ReadEventListQuery,
+  type ReadEventListView,
   type StorageOverviewView,
   type SystemBackupView,
   type SystemJobView,
+  type VsNfdProfileView,
 } from '@dorfteich/shared';
 
 import { AuthedRequest } from '../auth/auth.guard';
 import { ZodValidationPipe } from '../common/zod-validation.pipe';
+import { VsNfdProfileService } from '../settings/vs-nfd-profile.service';
 import { SiteAdminGuard } from './site-admin.guard';
 import { SystemAdminService } from './system-admin.service';
 
@@ -18,7 +23,17 @@ import { SystemAdminService } from './system-admin.service';
 @Controller('admin/system')
 @UseGuards(SiteAdminGuard)
 export class SystemAdminController {
-  constructor(private readonly system: SystemAdminService) {}
+  constructor(
+    private readonly system: SystemAdminService,
+    private readonly vsNfdProfile: VsNfdProfileService,
+  ) {}
+
+  /** Active VS-NfD mode + catalog verdict for the running configuration
+   * (issue #243, ADR 0027). Exposure only — the treatments are #244–#246. */
+  @Get('vs-nfd-profile')
+  vsNfd(): Promise<VsNfdProfileView> {
+    return this.vsNfdProfile.evaluate();
+  }
 
   @Get('jobs')
   async jobs(): Promise<SystemJobView[]> {
@@ -34,7 +49,7 @@ export class SystemAdminController {
   }
 
   @Get('backup')
-  backup(): SystemBackupView {
+  backup(): Promise<SystemBackupView> {
     return this.system.backup();
   }
 
@@ -45,6 +60,15 @@ export class SystemAdminController {
     return this.system.auditLog(query);
   }
 
+  /** Read-access trail queries (issue #224): "who read page X", "what did
+   * user Y read" — Site-Admin only, like the audit viewer above. */
+  @Get('read-events')
+  async readEvents(
+    @Query(new ZodValidationPipe(readEventListQuerySchema)) query: ReadEventListQuery,
+  ): Promise<ReadEventListView> {
+    return this.system.readEvents(query);
+  }
+
   @Get('storage')
   async storage(): Promise<StorageOverviewView> {
     return this.system.storage();

apps/api/src/admin/system-admin.service.ts

@@ -7,16 +7,21 @@ import {
   AUDIT_PAGE_SIZE,
   BACKUP_FRESH_MAX_AGE_HOURS,
   BACKUP_STATUS_FILE,
+  READ_EVENT_PAGE_SIZE,
   type AuditListQuery,
   type AuditListView,
   type BackupStatus,
   type JobTriggerResult,
+  type ReadEventListQuery,
+  type ReadEventListView,
   type StorageOverviewView,
   type SystemBackupView,
   type SystemJobView,
 } from '@dorfteich/shared';
 
 import { AuditService } from '../audit/audit.service';
+import { BackupTargetService } from '../backup/backup-target.service';
+import { MaintenanceStateService } from '../backup/maintenance-state.service';
 import { AppConfig } from '../config/app-config.service';
 import { PrismaService } from '../prisma/prisma.service';
 import { SchedulerService } from '../scheduler/scheduler.service';
@@ -35,6 +40,8 @@ export class SystemAdminService {
     private readonly scheduler: SchedulerService,
     private readonly audit: AuditService,
     private readonly config: AppConfig,
+    private readonly backupTarget: BackupTargetService,
+    private readonly maintenance: MaintenanceStateService,
   ) {}
 
   /**
@@ -89,8 +96,9 @@ export class SystemAdminService {
     return { outcome, job };
   }
 
-  /** The backup card mirrors status.json including the freshness verdict. */
-  backup(): SystemBackupView {
+  /** The backup card mirrors status.json including the freshness verdict,
+   * plus the off-host target state and restore progress (issue #103). */
+  async backup(): Promise<SystemBackupView> {
     const path = join(this.config.env.BACKUPS_DIR, BACKUP_STATUS_FILE);
     let status: BackupStatus | null = null;
     if (existsSync(path)) {
@@ -109,6 +117,8 @@ export class SystemAdminService {
       fresh: Number.isFinite(ageHours) && ageHours <= BACKUP_FRESH_MAX_AGE_HOURS,
       status,
       maxAgeHours: BACKUP_FRESH_MAX_AGE_HOURS,
+      remoteConfigured: (await this.backupTarget.resolveTarget()) !== null,
+      restore: this.maintenance.current(),
     };
   }
 
@@ -153,6 +163,66 @@ export class SystemAdminService {
     };
   }
 
+  /**
+   * The Site-Admin query path over the read-access trail (issue #224,
+   * ADR 0023) — evidence nobody can read is not evidence. Answers "who read
+   * page X" and "what did user Y read" within a period. API-only by design
+   * (no panel yet): the trail is an examiner's tool, not a daily screen —
+   * documented in data-model.md §read_events.
+   */
+  async readEvents(query: ReadEventListQuery): Promise<ReadEventListView> {
+    const where: Prisma.ReadEventWhereInput = {};
+    if (query.pageId) where.pageId = query.pageId;
+    if (query.actor) {
+      const actor = await this.prisma.user.findUnique({ where: { username: query.actor } });
+      // An unknown username matches nothing rather than everything.
+      where.actorId = actor?.id ?? '00000000-0000-0000-0000-000000000000';
+    }
+    if (query.channel) where.channel = query.channel;
+    if (query.from || query.to) {
+      where.occurredAt = {
+        ...(query.from ? { gte: query.from } : {}),
+        ...(query.to ? { lte: query.to } : {}),
+      };
+    }
+
+    const total = await this.prisma.readEvent.count({ where });
+    const pageCount = Math.max(1, Math.ceil(total / READ_EVENT_PAGE_SIZE));
+    const page = Math.min(query.page, pageCount);
+    const events = await this.prisma.readEvent.findMany({
+      where,
+      orderBy: { occurredAt: 'desc' },
+      skip: (page - 1) * READ_EVENT_PAGE_SIZE,
+      take: READ_EVENT_PAGE_SIZE,
+    });
+    // No FK on actor_id (evidence outlives accounts) — resolve what still
+    // exists in one query, show the bare id otherwise.
+    const actorIds = [...new Set(events.map((e) => e.actorId).filter((id): id is string => !!id))];
+    const actors = actorIds.length
+      ? await this.prisma.user.findMany({
+          where: { id: { in: actorIds } },
+          select: { id: true, username: true, displayName: true },
+        })
+      : [];
+    const actorById = new Map(actors.map((a) => [a.id, a]));
+    return {
+      entries: events.map((event) => ({
+        id: event.id,
+        occurredAt: event.occurredAt.toISOString(),
+        actor: event.actorId ? (actorById.get(event.actorId) ?? null) : null,
+        pageId: event.pageId,
+        pondId: event.pondId,
+        channel: event.channel,
+        classification: event.classification,
+        windowSeconds: event.windowSeconds,
+        details: (event.details as Record<string, unknown> | null) ?? null,
+      })),
+      page,
+      pageCount,
+      total,
+    };
+  }
+
   async storage(): Promise<StorageOverviewView> {
     const usages = await this.prisma.pondUsage.findMany({
       where: { pond: { deletedAt: null } },

apps/api/src/admin/user-admin.controller.ts

@@ -12,9 +12,11 @@ import {
   UseGuards,
 } from '@nestjs/common';
 import {
+  AdminCreateUserInput,
   AdminUserListQuery,
   AdminUserListView,
   AdminUserView,
+  adminCreateUserSchema,
   adminUserListQuerySchema,
   setSiteAdminSchema,
   setUserDisabledSchema,
@@ -31,6 +33,14 @@ import { UserAdminService } from './user-admin.service';
 export class UserAdminController {
   constructor(private readonly users: UserAdminService) {}
 
+  @Post()
+  async create(
+    @Body(new ZodValidationPipe(adminCreateUserSchema)) input: AdminCreateUserInput,
+    @Req() request: AuthedRequest,
+  ): Promise<AdminUserView> {
+    return this.users.createUser(request.user!, input);
+  }
+
   @Get()
   async list(
     @Query(new ZodValidationPipe(adminUserListQuerySchema)) query: AdminUserListQuery,

apps/api/src/admin/user-admin.e2e.db.test.ts

@@ -6,7 +6,7 @@ import { afterAll, beforeAll, describe, expect, it } from 'vitest';
 
 import { PondsService } from '../ponds/ponds.service';
 import { createTestApp, sessionCookieOf } from '../testing/test-app';
-import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { createTestPrisma, deletePondsWhere, hasTestDb, uniqueSuffix } from '../testing/test-db';
 import { UsersService } from '../users/users.service';
 
 /**
@@ -62,13 +62,71 @@ describe.skipIf(!hasTestDb)('user admin (e2e, issue #59)', () => {
   afterAll(async () => {
     const all = Object.values(ids);
     await prisma.session.deleteMany({ where: { userId: { in: all } } });
-    await prisma.pond.deleteMany({ where: { ownerId: { in: all } } });
+    await deletePondsWhere(prisma, { ownerId: { in: all } });
     await prisma.userIdentity.deleteMany({ where: { userId: { in: all } } });
     await prisma.user.deleteMany({ where: { id: { in: all } } });
     await prisma.$disconnect();
     await app.close();
   });
 
+  it('creates an account that can log in right away, with a personal pond (issue #331)', async () => {
+    const username = `ua-created-${suffix}`;
+    const res = await api()
+      .post('/api/v1/admin/users')
+      .set('Cookie', cookies.admin1!)
+      .send({
+        username,
+        email: `${username}@example.org`,
+        displayName: 'UA Created',
+        password,
+        locale: 'de',
+      })
+      .expect(201);
+    const created = res.body as { id: string; status: string };
+    ids.created = created.id;
+    // No verification hop: the admin vouched for the address.
+    expect(created.status).toBe('ACTIVE');
+    await api()
+      .post('/api/v1/auth/login')
+      .send({ usernameOrEmail: username, password })
+      .expect(200);
+    // The personal pond exists exactly like after self-registration.
+    expect(await prisma.pond.count({ where: { ownerId: created.id, type: 'PERSONAL' } })).toBe(1);
+  });
+
+  it('rejects duplicate usernames with a field-level conflict', async () => {
+    await api()
+      .post('/api/v1/admin/users')
+      .set('Cookie', cookies.admin1!)
+      .send({
+        username: `ua-created-${suffix}`,
+        email: `ua-created-other-${suffix}@example.org`,
+        displayName: 'UA Dup',
+        password,
+        locale: 'en',
+      })
+      .expect(409)
+      .expect((r) =>
+        expect((r.body as { details: Record<string, string[]> }).details.username).toEqual([
+          'validation.taken',
+        ]),
+      );
+  });
+
+  it('refuses creation for non-admins', async () => {
+    await api()
+      .post('/api/v1/admin/users')
+      .set('Cookie', cookies.bob!)
+      .send({
+        username: `ua-sneak-${suffix}`,
+        email: `ua-sneak-${suffix}@example.org`,
+        displayName: 'UA Sneak',
+        password,
+        locale: 'en',
+      })
+      .expect(403);
+  });
+
   it('lists and searches users (Site-Admin only)', async () => {
     const res = await api()
       .get(`/api/v1/admin/users?q=ua-bob-${suffix}`)

apps/api/src/admin/user-admin.service.ts

@@ -1,5 +1,6 @@
 import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
 import {
+  AdminCreateUserInput,
   AdminUserListQuery,
   AdminUserListView,
   AdminUserStatus,
@@ -10,7 +11,9 @@ import { PinoLogger } from 'nestjs-pino';
 
 import { AuthService } from '../auth/auth.service';
 import { AuditService } from '../audit/audit.service';
+import { PondsService } from '../ponds/ponds.service';
 import { PrismaService } from '../prisma/prisma.service';
+import { UsersService } from '../users/users.service';
 import { PseudonymizationService } from './pseudonymization.service';
 
 /**
@@ -27,12 +30,33 @@ export class UserAdminService {
     private readonly prisma: PrismaService,
     private readonly pseudonymizer: PseudonymizationService,
     private readonly auth: AuthService,
+    private readonly users: UsersService,
+    private readonly ponds: PondsService,
     private readonly audit: AuditService,
     private readonly logger: PinoLogger,
   ) {
     this.logger.setContext(UserAdminService.name);
   }
 
+  /**
+   * Creates an account on behalf of a user (issue #331). The e-mail is
+   * marked verified immediately — the admin vouches for the address — and
+   * the personal pond is provisioned exactly like the verify-email path
+   * does, so the account is indistinguishable from a self-registered one.
+   */
+  async createUser(actor: User, input: AdminCreateUserInput): Promise<AdminUserView> {
+    const user = await this.users.createUser(input);
+    const verified = await this.users.markEmailVerified(user.id);
+    await this.ponds.ensurePersonalPond(verified);
+    await this.audit.record({
+      action: 'user.created_by_admin',
+      actorId: actor.id,
+      targetType: 'user',
+      targetId: user.id,
+    });
+    return this.viewOf(verified, await this.pondCountOf(user.id));
+  }
+
   async list(query: AdminUserListQuery): Promise<AdminUserListView> {
     const q = query.q?.trim();
     const where: Prisma.UserWhereInput = q
@@ -115,7 +139,9 @@ export class UserAdminService {
     if (!value && user.isSiteAdmin) await this.assertNotLastSiteAdmin();
     const updated = await this.prisma.user.update({
       where: { id },
-      data: { isSiteAdmin: value },
+      // A manual toggle takes ownership of the flag: the IdP mapping
+      // (#217) may only revoke what it itself set.
+      data: { isSiteAdmin: value, isSiteAdminManaged: false },
     });
     await this.audit.record({
       action: 'user.site_admin_set',

apps/api/src/app.module.ts

@@ -1,11 +1,15 @@
-import { Module } from '@nestjs/common';
+import { MiddlewareConsumer, Module, NestModule } from '@nestjs/common';
 import { APP_FILTER } from '@nestjs/core';
 import { LoggerModule } from 'nestjs-pino';
 
 import { AdminModule } from './admin/admin.module';
 import { AuditModule } from './audit/audit.module';
 import { AuthModule } from './auth/auth.module';
+import { BackupModule } from './backup/backup.module';
+import { BrandingModule } from './branding/branding.module';
 import { ApiExceptionFilter } from './common/api-exception.filter';
+import { maskTokenParam } from './common/mask-token-param';
+import { SecurityHeadersMiddleware } from './common/security-headers.middleware';
 import { CommentsModule } from './comments/comments.module';
 import { CompactionModule } from './compaction/compaction.module';
 import { AppConfig } from './config/app-config.service';
@@ -13,19 +17,24 @@ import { ConfigModule } from './config/config.module';
 import { FilesModule } from './files/files.module';
 import { GrantsModule } from './grants/grants.module';
 import { HealthModule } from './health/health.module';
+import { HomeModule } from './home/home.module';
+import { FontsModule } from './fonts/fonts.module';
 import { ImportExportModule } from './import-export/import-export.module';
 import { LabelsModule } from './labels/labels.module';
 import { LegalModule } from './legal/legal.module';
 import { LinksModule } from './links/links.module';
 import { MailModule } from './mail/mail.module';
+import { McpModule } from './mcp/mcp.module';
 import { MembersModule } from './members/members.module';
 import { PagesModule } from './pages/pages.module';
 import { PermissionsModule } from './permissions/permissions.module';
 import { PluginsModule } from './plugins/plugins.module';
 import { PondsModule } from './ponds/ponds.module';
 import { PrismaModule } from './prisma/prisma.module';
+import { PublicApiModule } from './public-api/public-api.module';
 import { PublicModule } from './public/public.module';
 import { RateLimitModule } from './rate-limit/rate-limit.module';
+import { ReadTrailModule } from './read-trail/read-trail.module';
 import { SearchModule } from './search/search.module';
 import { SettingsModule } from './settings/settings.module';
 import { SetupModule } from './setup/setup.module';
@@ -33,6 +42,7 @@ import { TrashModule } from './trash/trash.module';
 import { UsersModule } from './users/users.module';
 import { NotificationsModule } from './notifications/notifications.module';
 import { WatchesModule } from './watches/watches.module';
+import { FavoritesModule } from './favorites/favorites.module';
 import { VersionsModule } from './versions/versions.module';
 
 @Module({
@@ -40,11 +50,16 @@ import { VersionsModule } from './versions/versions.module';
     ConfigModule,
     PrismaModule,
     AuditModule,
+    ReadTrailModule,
     RateLimitModule,
     MailModule,
     SettingsModule,
-    // Before AuthModule: global guards run in registration order, and the
-    // setup gate must win over AuthGuard's 401 while setup is pending.
+    // Before SetupModule and AuthModule: global guards run in registration
+    // order, and the maintenance gate (in-app restore, issue #103) must
+    // answer before anything touches the mid-restore database.
+    BackupModule,
+    // Before AuthModule: the setup gate must win over AuthGuard's 401 while
+    // setup is pending.
     SetupModule,
     UsersModule,
     PermissionsModule,
@@ -52,6 +67,7 @@ import { VersionsModule } from './versions/versions.module';
     PagesModule,
     CommentsModule,
     WatchesModule,
+    FavoritesModule,
     NotificationsModule,
     FilesModule,
     TrashModule,
@@ -59,11 +75,16 @@ import { VersionsModule } from './versions/versions.module';
     VersionsModule,
     LabelsModule,
     LegalModule,
+    HomeModule,
     LinksModule,
     SearchModule,
     GrantsModule,
     MembersModule,
     PublicModule,
+    PublicApiModule,
+    McpModule,
+    BrandingModule,
+    FontsModule,
     ImportExportModule,
     PluginsModule,
     AuthModule,
@@ -78,6 +99,11 @@ import { VersionsModule } from './versions/versions.module';
           autoLogging: config.env.NODE_ENV !== 'test',
           // Request bodies are never logged (operations.md logging rules).
           redact: { paths: ['req.headers.authorization', 'req.headers.cookie'], remove: true },
+          // Feed tokens travel as `?token=` (issue #191) — mask them so the
+          // request log never stores the credential.
+          serializers: {
+            req: (req: { url?: string }) => ({ ...req, url: maskTokenParam(req.url) }),
+          },
         },
       }),
     }),
@@ -85,4 +111,10 @@ import { VersionsModule } from './versions/versions.module';
   ],
   providers: [{ provide: APP_FILTER, useClass: ApiExceptionFilter }],
 })
-export class AppModule {}
+export class AppModule implements NestModule {
+  configure(consumer: MiddlewareConsumer): void {
+    // Module-level (not main.ts) so createTestApp boots the identical
+    // security-header/CORS middleware — see security-headers.middleware.ts.
+    consumer.apply(SecurityHeadersMiddleware).forRoutes('{*path}');
+  }
+}

apps/api/src/audit/audit-actions.ts

@@ -0,0 +1,75 @@
+/**
+ * The audit event catalogue (issue #201): every action id the trail may
+ * carry, with the severity the stdout line is stamped with. This const is
+ * the CODE half of the published catalogue in
+ * `docs/architecture/audit-events.md` — `audit-catalogue.test.ts` fails
+ * whenever the two drift, so an id cannot be added, renamed, or removed
+ * without its documentation moving in the same commit.
+ *
+ * Compatibility promise (the reason this exists): ids are never repurposed.
+ * New events may be added (minor catalogue version); an id that stops being
+ * emitted is retired in the catalogue document, its meaning frozen forever —
+ * so an operator's SIEM rules survive our releases.
+ */
+export const AUDIT_EVENTS = {
+  'api.token_created': { severity: 'info' },
+  'api.token_revoked': { severity: 'info' },
+  'api.write': { severity: 'info' },
+  'audit.pruned': { severity: 'info' },
+  'auth.email_verified': { severity: 'info' },
+  'auth.identity_linked': { severity: 'notice' },
+  'auth.login_failed': { severity: 'warning' },
+  'auth.login_succeeded': { severity: 'info' },
+  'auth.password_reset': { severity: 'notice' },
+  'auth.proxy_rejected': { severity: 'warning' },
+  'auth.signup': { severity: 'info' },
+  'backup.restore_requested': { severity: 'warning' },
+  'backup.run_triggered': { severity: 'info' },
+  'backup.settings_changed': { severity: 'notice' },
+  'file.integrity_failed': { severity: 'critical' },
+  'grant.created': { severity: 'notice' },
+  'grant.deleted': { severity: 'notice' },
+  'invitation.accepted': { severity: 'notice' },
+  'invitation.created': { severity: 'info' },
+  'invitation.revoked': { severity: 'info' },
+  'job.triggered': { severity: 'info' },
+  'member.added': { severity: 'notice' },
+  'member.removed': { severity: 'notice' },
+  'member.role_changed': { severity: 'notice' },
+  'page.classification_lowered': { severity: 'warning' },
+  'page.classification_raised': { severity: 'notice' },
+  'plugin.installed': { severity: 'notice' },
+  'plugin.rejected': { severity: 'warning' },
+  'plugin.mode_set': { severity: 'notice' },
+  'plugin.pond_toggled': { severity: 'info' },
+  'plugin.uninstalled': { severity: 'notice' },
+  'pond.archived': { severity: 'notice' },
+  'pond.purged': { severity: 'notice' },
+  'quota.override_cleared': { severity: 'notice' },
+  'quota.override_set': { severity: 'notice' },
+  'read_trail.pruned': { severity: 'info' },
+  'settings.changed': { severity: 'notice' },
+  'branding.changed': { severity: 'notice' },
+  'font.uploaded': { severity: 'notice' },
+  'font.deleted': { severity: 'notice' },
+  'setup.admin_created': { severity: 'notice' },
+  'setup.completed': { severity: 'info' },
+  'setup.preseeded': { severity: 'info' },
+  'setup.smtp_stored': { severity: 'info' },
+  'user.created_by_admin': { severity: 'notice' },
+  'user.deleted': { severity: 'notice' },
+  'user.disabled_set': { severity: 'notice' },
+  'user.pseudonymized': { severity: 'notice' },
+  'user.site_admin_set': { severity: 'notice' },
+  'user.verification_resent': { severity: 'info' },
+} as const satisfies Record<string, { severity: AuditSeverity }>;
+
+/** Severity vocabulary of the catalogue — syslog-inspired, four levels are
+ * enough for rule routing (critical pages someone, warning feeds detection,
+ * notice is configuration drift, info is lifecycle noise). */
+export type AuditSeverity = 'info' | 'notice' | 'warning' | 'critical';
+
+/** A catalogued action id — the ONLY thing {@link AuditService.record}
+ * accepts, so an uncatalogued event cannot be emitted (compile-time), and
+ * the doc fence keeps the catalogue document in step (test-time). */
+export type AuditAction = keyof typeof AUDIT_EVENTS;

apps/api/src/audit/audit-catalogue.test.ts

@@ -0,0 +1,48 @@
+import { readFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+import { describe, expect, it } from 'vitest';
+
+import { AUDIT_EVENTS } from './audit-actions';
+
+/**
+ * The fence that keeps the published audit catalogue and the code together
+ * (issue #201): every id in `AUDIT_EVENTS` must appear as an event row in
+ * `docs/architecture/audit-events.md` with the same severity, and the
+ * document may not describe ids the code does not know. Emission of an
+ * uncatalogued id is already a TYPE error (AuditAction union) — this test
+ * covers the half the compiler cannot see: the document.
+ */
+// __dirname, not import.meta: the api package compiles CJS (tsconfig has no
+// nodenext module), and vitest resolves both — the compiler only the former.
+const doc = readFileSync(join(__dirname, '../../../../docs/architecture/audit-events.md'), 'utf8');
+
+/** Event rows are `| \`ns.event\` | trigger | severity | …` — the dot in the
+ * id keeps field-set rows (`msg`, `severity`, …) out of the match. The
+ * namespace may carry an underscore since `read_trail.*` (issue #224). */
+function documentedEvents(): Map<string, string> {
+  const events = new Map<string, string>();
+  for (const line of doc.split('\n')) {
+    const id = /^\| `([a-z_]+\.[a-z_]+)` +\|/.exec(line)?.[1];
+    if (!id) continue;
+    const cells = line.split('|').map((cell) => cell.trim());
+    // cells[0] is the empty string before the leading pipe.
+    events.set(id, cells[3] ?? '');
+  }
+  return events;
+}
+
+describe('audit catalogue fence (issue #201)', () => {
+  it('documents exactly the ids the code can emit', () => {
+    const documented = documentedEvents();
+    const inCode = Object.keys(AUDIT_EVENTS).sort();
+    expect([...documented.keys()].sort()).toEqual(inCode);
+  });
+
+  it('documents each id with the severity the code stamps', () => {
+    const documented = documentedEvents();
+    for (const [action, { severity }] of Object.entries(AUDIT_EVENTS)) {
+      expect(`${action}: ${documented.get(action)}`).toBe(`${action}: ${severity}`);
+    }
+  });
+});

apps/api/src/audit/audit-retention.e2e.db.test.ts

@@ -0,0 +1,90 @@
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { AuditRetentionService } from './audit-retention.service';
+
+const DAY = 24 * 60 * 60 * 1000;
+
+/**
+ * Audit-trail retention (issue #196): entries past `audit.retentionDays`
+ * are pruned, newer ones stay, and the pruning itself lands in the trail
+ * (`audit.pruned` with count and cutoff) so the gap is explainable.
+ */
+describe.skipIf(!hasTestDb)('audit retention (e2e, issue #196)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const marker = `retention-${suffix}`;
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    // A short period so ages are unambiguous; written straight to the row
+    // BEFORE the app boots (the settings cache is in-process and fills on
+    // first read). The key is cleaned afterAll.
+    await prisma.instanceSetting.upsert({
+      where: { key: 'audit.retentionDays' },
+      create: { key: 'audit.retentionDays', value: 30 },
+      update: { value: 30 },
+    });
+    app = await createTestApp();
+  });
+
+  afterAll(async () => {
+    await prisma.instanceSetting.deleteMany({ where: { key: 'audit.retentionDays' } });
+    await prisma.auditEntry.deleteMany({
+      where: { OR: [{ targetId: { contains: suffix } }, { action: 'audit.pruned' }] },
+    });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('prunes entries past the period, keeps newer ones, and records the pruning', async () => {
+    await prisma.auditEntry.createMany({
+      data: [
+        {
+          action: 'test.old',
+          targetType: 'test',
+          targetId: marker,
+          at: new Date(Date.now() - 40 * DAY),
+        },
+        {
+          action: 'test.older',
+          targetType: 'test',
+          targetId: marker,
+          at: new Date(Date.now() - 400 * DAY),
+        },
+        {
+          action: 'test.fresh',
+          targetType: 'test',
+          targetId: marker,
+          at: new Date(Date.now() - 5 * DAY),
+        },
+      ],
+    });
+
+    const pruned = await app.get(AuditRetentionService).pruneExpired();
+    expect(pruned).toBeGreaterThanOrEqual(2);
+
+    const remaining = await prisma.auditEntry.findMany({ where: { targetId: marker } });
+    expect(remaining.map((entry) => entry.action)).toEqual(['test.fresh']);
+
+    // The gap is explainable: the pruning run is itself on the trail.
+    const prunedEvent = await prisma.auditEntry.findFirst({
+      where: { action: 'audit.pruned' },
+      orderBy: { at: 'desc' },
+    });
+    expect(prunedEvent).not.toBeNull();
+    expect(prunedEvent!.details).toMatchObject({ retentionDays: 30 });
+    expect((prunedEvent!.details as { count: number }).count).toBeGreaterThanOrEqual(2);
+  });
+
+  it('is a no-op when nothing is due', async () => {
+    const pruned = await app.get(AuditRetentionService).pruneExpired();
+    expect(pruned).toBe(0);
+    // The fresh marker entry from the first test is untouched.
+    expect(await prisma.auditEntry.count({ where: { targetId: marker } })).toBe(1);
+  });
+});

apps/api/src/audit/audit-retention.service.ts

@@ -0,0 +1,47 @@
+import { Injectable } from '@nestjs/common';
+import { PinoLogger } from 'nestjs-pino';
+
+import { ClockService } from '../common/clock.service';
+import { PrismaService } from '../prisma/prisma.service';
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+
+import { AuditService } from './audit.service';
+
+const MS_PER_DAY = 24 * 60 * 60 * 1000;
+
+/**
+ * Audit-trail retention (issue #196): the daily job deletes `audit_log`
+ * entries older than the configurable `audit.retentionDays` (default one
+ * year) and records the deletion itself (`audit.pruned` with count and
+ * cutoff) so a gap in the trail is always explainable. Separate from
+ * {@link AuditService} because the settings service audits its own writes
+ * — folding retention into AuditService would close a constructor cycle.
+ * The read-access trail (#224) is deliberately not covered here.
+ */
+@Injectable()
+export class AuditRetentionService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly settings: InstanceSettingsService,
+    private readonly audit: AuditService,
+    private readonly clock: ClockService,
+    private readonly logger: PinoLogger,
+  ) {
+    this.logger.setContext(AuditRetentionService.name);
+  }
+
+  async pruneExpired(): Promise<number> {
+    const retentionDays = await this.settings.get('audit.retentionDays');
+    const cutoff = new Date(this.clock.now().getTime() - retentionDays * MS_PER_DAY);
+    const { count } = await this.prisma.auditEntry.deleteMany({
+      where: { at: { lt: cutoff } },
+    });
+    if (count > 0) {
+      await this.audit.record({
+        action: 'audit.pruned',
+        details: { count, cutoff: cutoff.toISOString(), retentionDays },
+      });
+    }
+    return count;
+  }
+}

apps/api/src/audit/audit.module.ts

@@ -1,7 +1,16 @@
-import { Global, Module } from '@nestjs/common';
+import { Global, Module, OnModuleInit } from '@nestjs/common';
 
+import { CommonModule } from '../common/common.module';
+import { SchedulerModule } from '../scheduler/scheduler.module';
+import { SchedulerService } from '../scheduler/scheduler.service';
+import { SettingsModule } from '../settings/settings.module';
+
+import { AuditRetentionService } from './audit-retention.service';
 import { AuditService } from './audit.service';
 
+/** Daily, per operations.md's maintenance-jobs table (issue #196). */
+const AUDIT_RETENTION_CADENCE_SECONDS = 24 * 60 * 60;
+
 /**
  * Global because the audit trail cuts across nearly every feature module
  * (auth, grants, members, admin, plugins, setup) — like PrismaModule, one
@@ -9,7 +18,23 @@ import { AuditService } from './audit.service';
  */
 @Global()
 @Module({
-  providers: [AuditService],
+  imports: [CommonModule, SchedulerModule, SettingsModule],
+  providers: [AuditService, AuditRetentionService],
   exports: [AuditService],
 })
-export class AuditModule {}
+export class AuditModule implements OnModuleInit {
+  constructor(
+    private readonly scheduler: SchedulerService,
+    private readonly retention: AuditRetentionService,
+  ) {}
+
+  onModuleInit(): void {
+    this.scheduler.register({
+      name: 'audit-retention',
+      cadenceSeconds: AUDIT_RETENTION_CADENCE_SECONDS,
+      run: async () => {
+        await this.retention.pruneExpired();
+      },
+    });
+  }
+}

apps/api/src/audit/audit.service.ts

@@ -4,9 +4,13 @@ import { PinoLogger } from 'nestjs-pino';
 
 import { PrismaService } from '../prisma/prisma.service';
 
+import { AUDIT_EVENTS, AuditAction } from './audit-actions';
+
 export interface AuditEvent {
-  /** Stable dot-namespaced id, e.g. `grant.created` — the UI translates it. */
-  action: string;
+  /** Stable dot-namespaced id from the catalogue (issue #201,
+   * docs/architecture/audit-events.md) — the UI translates it, SIEM rules
+   * key on it. The union makes an uncatalogued emission a type error. */
+  action: AuditAction;
   /** The acting user; null/undefined for anonymous events. */
   actorId?: string | null;
   targetType?: string;
@@ -37,7 +41,15 @@ export class AuditService {
   async record(event: AuditEvent): Promise<void> {
     const { action, actorId, targetType, targetId, details } = event;
     this.logger.info(
-      { actor: actorId ?? null, targetType, targetId, ...details },
+      // `severity` is the catalogue's routing hint for SIEM rules (#201) —
+      // pino's own `level` stays 30/info so log transport is unaffected.
+      {
+        severity: AUDIT_EVENTS[action].severity,
+        actor: actorId ?? null,
+        targetType,
+        targetId,
+        ...details,
+      },
       `audit: ${action}`,
     );
     try {

apps/api/src/auth/auth.controller.ts

@@ -1,5 +1,6 @@
 import { Body, Controller, Get, HttpCode, Post, Req, Res } from '@nestjs/common';
 import {
+  AuthMethodsView,
   CurrentUser as CurrentUserShape,
   LoginInput,
   SignupInput,
@@ -20,13 +21,15 @@ import { InstanceSettingsService } from '../settings/instance-settings.service';
 import { SetupExempt } from '../setup/setup.guard';
 import {
   AuthedRequest,
+  LocalCredentialFlow,
   Public,
   SESSION_COOKIE,
   setSessionCookie,
   toCurrentUser,
 } from './auth.guard';
 import { AuthService } from './auth.service';
-import { SessionsService } from './sessions.service';
+import { OidcService } from './oidc.service';
+import { SessionsService, sessionAbsoluteMs } from './sessions.service';
 
 @AuthenticatedOnly() // routes reachable without a session opt out via @Public
 @Controller('auth')
@@ -36,6 +39,7 @@ export class AuthController {
     private readonly sessions: SessionsService,
     private readonly config: AppConfig,
     private readonly settings: InstanceSettingsService,
+    private readonly oidc: OidcService,
   ) {}
 
   /** Public: the SPA hides the signup route while registration is closed. */
@@ -45,8 +49,21 @@ export class AuthController {
     return { mode: await this.settings.get('auth.registrationMode') };
   }
 
+  /** Public: what the login screen offers (issue #214) — the local form
+   * and/or the deploy-configured OIDC provider. */
+  @SetupExempt()
+  @Public()
+  @Get('methods')
+  methods(): AuthMethodsView {
+    return {
+      local: this.config.env.AUTH_LOCAL_ENABLED,
+      oidc: this.oidc.enabled ? { label: this.oidc.providerLabel } : null,
+    };
+  }
+
   @Public()
   @Post('signup')
+  @LocalCredentialFlow()
   @HttpCode(201)
   @RateLimit({ scope: 'signup', limit: 5, windowSeconds: 60 * 60 })
   async signup(@Body(new ZodValidationPipe(signupInputSchema)) input: SignupInput): Promise<void> {
@@ -55,6 +72,7 @@ export class AuthController {
 
   @Public()
   @Post('verify-email')
+  @LocalCredentialFlow()
   @HttpCode(204)
   @RateLimit({ scope: 'verify-email', limit: 20, windowSeconds: 60 * 60 })
   async verifyEmail(
@@ -65,6 +83,7 @@ export class AuthController {
 
   @Public()
   @Post('resend-verification')
+  @LocalCredentialFlow()
   @HttpCode(204)
   @RateLimit({ scope: 'resend-verification', limit: 5, windowSeconds: 60 * 60 })
   async resendVerification(
@@ -78,6 +97,7 @@ export class AuthController {
   @SetupExempt()
   @Public()
   @Post('login')
+  @LocalCredentialFlow()
   @HttpCode(200)
   @RateLimit({ scope: 'login', limit: 10, windowSeconds: 60 })
   async login(
@@ -90,7 +110,12 @@ export class AuthController {
       input.password,
       request.headers['user-agent'],
     );
-    setSessionCookie(response, sessionToken, this.config.env.NODE_ENV === 'production');
+    setSessionCookie(
+      response,
+      sessionToken,
+      this.config.env.NODE_ENV === 'production',
+      sessionAbsoluteMs(this.config.env),
+    );
     return toCurrentUser(user);
   }
 
@@ -116,6 +141,7 @@ export class AuthController {
 
   @Public()
   @Post('forgot-password')
+  @LocalCredentialFlow()
   @HttpCode(204)
   @RateLimit({ scope: 'forgot-password', limit: 5, windowSeconds: 60 * 60 })
   async forgotPassword(
@@ -126,6 +152,7 @@ export class AuthController {
 
   @Public()
   @Post('reset-password')
+  @LocalCredentialFlow()
   @HttpCode(204)
   @RateLimit({ scope: 'reset-password', limit: 10, windowSeconds: 60 * 60 })
   async resetPassword(

apps/api/src/auth/auth.e2e.db.test.ts

@@ -4,7 +4,7 @@ import request from 'supertest';
 import { afterAll, beforeAll, describe, expect, it } from 'vitest';
 
 import { createTestApp, sessionCookieOf } from '../testing/test-app';
-import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { createTestPrisma, deletePondsWhere, hasTestDb, uniqueSuffix } from '../testing/test-db';
 
 describe.skipIf(!hasTestDb)('auth flows (e2e)', () => {
   let app: INestApplication;
@@ -46,7 +46,7 @@ describe.skipIf(!hasTestDb)('auth flows (e2e)', () => {
 
   afterAll(async () => {
     // Verified users own a personal pond (#21) — remove it before them.
-    await prisma.pond.deleteMany({ where: { owner: { username: { contains: suffix } } } });
+    await deletePondsWhere(prisma, { owner: { username: { contains: suffix } } });
     await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
     await prisma.mailOutbox.deleteMany({ where: { toAddress: { contains: suffix } } });
     await prisma.$disconnect();

apps/api/src/auth/auth.guard.ts

@@ -3,6 +3,7 @@ import {
   ExecutionContext,
   ForbiddenException,
   Injectable,
+  NotFoundException,
   SetMetadata,
   UnauthorizedException,
   createParamDecorator,
@@ -13,6 +14,7 @@ import type { User } from '@prisma/client';
 import type { Request, Response } from 'express';
 
 import { AppConfig } from '../config/app-config.service';
+import { ProxyIdentityService } from './proxy-identity.service';
 import { SessionsService } from './sessions.service';
 
 export const SESSION_COOKIE = 'dt_session';
@@ -21,6 +23,18 @@ const IS_PUBLIC_KEY = 'isPublic';
 /** Marks a route as reachable without a session (login, signup, healthz…). */
 export const Public = (): MethodDecorator & ClassDecorator => SetMetadata(IS_PUBLIC_KEY, true);
 
+export const LOCAL_CREDENTIAL_KEY = 'isLocalCredentialFlow';
+/**
+ * Marks a route as part of the LOCAL credential machinery (issue #216,
+ * ADR 0021): password login, signup, e-mail verification, password
+ * forgot/reset/change. With `AUTH_LOCAL_ENABLED=false` every marked route
+ * answers 404 (existence hidden, the switch precedent) — and the
+ * enumeration fence in `local-auth-switch.e2e.db.test.ts` fails when an
+ * auth route is neither marked nor on its reviewed allowlist, so a new
+ * credential flow cannot ship unswitched by accident.
+ */
+export const LocalCredentialFlow = (): MethodDecorator => SetMetadata(LOCAL_CREDENTIAL_KEY, true);
+
 export interface AuthedRequest extends Request {
   user?: User;
   sessionId?: string;
@@ -49,13 +63,23 @@ export function toCurrentUser(user: User): CurrentUserShape {
   };
 }
 
-/** Session cookie contract shared by login and the setup wizard (issue #80). */
-export function setSessionCookie(response: Response, token: string, production: boolean): void {
+/**
+ * Session cookie contract shared by login and the setup wizard (issue #80).
+ * `maxAgeMs` follows the configured absolute session bound (#190) — the
+ * server-side idle/absolute checks are authoritative, the cookie merely
+ * stops outliving them.
+ */
+export function setSessionCookie(
+  response: Response,
+  token: string,
+  production: boolean,
+  maxAgeMs: number,
+): void {
   response.cookie(SESSION_COOKIE, token, {
     httpOnly: true,
     sameSite: 'lax',
     secure: production,
-    maxAge: 30 * 24 * 60 * 60 * 1000,
+    maxAge: maxAgeMs,
     path: '/',
   });
 }
@@ -74,19 +98,38 @@ export class AuthGuard implements CanActivate {
     private readonly reflector: Reflector,
     private readonly sessions: SessionsService,
     private readonly config: AppConfig,
+    private readonly proxyIdentity: ProxyIdentityService,
   ) {}
 
   async canActivate(context: ExecutionContext): Promise<boolean> {
     const request = context.switchToHttp().getRequest<AuthedRequest>();
+
+    // The hard local-auth switch (issue #216): marked credential routes
+    // disappear entirely — before any session or CSRF logic runs.
+    if (!this.config.env.AUTH_LOCAL_ENABLED) {
+      const isLocalFlow = this.reflector.getAllAndOverride<boolean>(LOCAL_CREDENTIAL_KEY, [
+        context.getHandler(),
+        context.getClass(),
+      ]);
+      if (isLocalFlow) throw new NotFoundException();
+    }
+
     const rawToken = (request.cookies as Record<string, string> | undefined)?.[SESSION_COOKIE];
 
     if (rawToken && MUTATING_METHODS.has(request.method)) {
       this.assertSameOrigin(request);
     }
 
+    // Trusted-proxy identity first (issue #215): when the perimeter
+    // authenticates, its header IS the identity for this request — a
+    // session cookie riding along never escalates beyond it, and an
+    // untrusted peer carrying the header is rejected inside resolve().
+    const proxyUser = await this.proxyIdentity.resolve(request);
+    if (proxyUser) {
+      request.user = proxyUser;
+    } else if (rawToken) {
       // Attach the user whenever the cookie is valid — public routes may
       // still want to know who is asking.
-    if (rawToken) {
       const validated = await this.sessions.validate(rawToken);
       if (validated) {
         request.user = validated.user;
@@ -105,13 +148,27 @@ export class AuthGuard implements CanActivate {
     return true;
   }
 
+  /**
+   * Fail closed (#189): a cookie-carrying mutation must prove its origin —
+   * browsers always send `Origin` on cross- and same-origin mutations, so a
+   * missing header means "not a browser page of ours" and is rejected like a
+   * mismatch. Non-browser clients (curl, scripts) either send a matching
+   * `Origin` explicitly or authenticate with a PAT/bearer token and no
+   * cookie, which never reaches this check — the exception for them is
+   * structural (bound to the cookie), never a header loophole.
+   */
   private assertSameOrigin(request: Request): void {
     const origin = request.headers.origin ?? request.headers.referer;
-    // Non-browser clients (curl, supertest) send neither header; SameSite
-    // cookies already stop cross-site browser requests without Origin.
-    if (!origin) return;
+    if (!origin) throw new ForbiddenException({ code: 'csrf_origin_mismatch' });
     const expected = new URL(this.config.env.APP_BASE_URL).origin;
-    if (new URL(origin).origin !== expected) {
+    let actual: string;
+    try {
+      actual = new URL(origin).origin;
+    } catch {
+      // An unparsable Origin/Referer is a broken or hostile client, not ours.
+      throw new ForbiddenException({ code: 'csrf_origin_mismatch' });
+    }
+    if (actual !== expected) {
       throw new ForbiddenException({ code: 'csrf_origin_mismatch' });
     }
   }

apps/api/src/auth/auth.module.ts

@@ -1,6 +1,10 @@
-import { Module } from '@nestjs/common';
+import { Logger, Module, OnModuleInit } from '@nestjs/common';
 import { APP_GUARD } from '@nestjs/core';
 
+import { AppConfig } from '../config/app-config.service';
+import { GrantsModule } from '../grants/grants.module';
+import { InvitationsModule } from '../invitations/invitations.module';
+
 import { MailModule } from '../mail/mail.module';
 import { PondsModule } from '../ponds/ponds.module';
 import { UsersModule } from '../users/users.module';
@@ -8,18 +12,42 @@ import { AuthController } from './auth.controller';
 import { AuthGuard } from './auth.guard';
 import { AuthService } from './auth.service';
 import { AuthTokensService } from './auth-tokens.service';
+import { ClaimMappingService } from './claim-mapping.service';
+import { OidcController } from './oidc.controller';
+import { OidcService } from './oidc.service';
+import { ProxyIdentityService } from './proxy-identity.service';
 import { SessionsModule } from './sessions.module';
 
 @Module({
-  imports: [UsersModule, MailModule, SessionsModule, PondsModule],
-  controllers: [AuthController],
+  imports: [UsersModule, MailModule, SessionsModule, PondsModule, GrantsModule, InvitationsModule],
+  controllers: [AuthController, OidcController],
   providers: [
     AuthService,
     AuthTokensService,
+    ClaimMappingService,
+    OidcService,
+    ProxyIdentityService,
     // Global default-protected: every route needs a session unless it
     // opts out with @Public().
     { provide: APP_GUARD, useClass: AuthGuard },
   ],
-  exports: [AuthTokensService, AuthService],
+  exports: [AuthTokensService, AuthService, OidcService],
 })
-export class AuthModule {}
+export class AuthModule implements OnModuleInit {
+  constructor(
+    private readonly config: AppConfig,
+    private readonly oidc: OidcService,
+    private readonly proxyIdentity: ProxyIdentityService,
+  ) {}
+
+  onModuleInit(): void {
+    // #216: local auth off without ANY external path means nobody can ever
+    // sign in — loudly stated at boot, because the operator will otherwise
+    // discover it at the login screen.
+    if (!this.config.env.AUTH_LOCAL_ENABLED && !this.oidc.enabled && !this.proxyIdentity.enabled) {
+      new Logger(AuthModule.name).warn(
+        'AUTH_LOCAL_ENABLED=false with neither OIDC nor proxy authentication configured — no sign-in path exists',
+      );
+    }
+  }
+}

apps/api/src/auth/auth.service.ts

@@ -9,6 +9,7 @@ import { User } from '@prisma/client';
 import { PinoLogger } from 'nestjs-pino';
 
 import { AppConfig } from '../config/app-config.service';
+import { InvitationsService } from '../invitations/invitations.service';
 import { MailService } from '../mail/mail.service';
 import { PondsService } from '../ponds/ponds.service';
 import { AuditService } from '../audit/audit.service';
@@ -33,6 +34,7 @@ export class AuthService {
     private readonly sessions: SessionsService,
     private readonly mail: MailService,
     private readonly ponds: PondsService,
+    private readonly invitations: InvitationsService,
     private readonly rateLimits: RateLimitService,
     private readonly audit: AuditService,
     private readonly config: AppConfig,
@@ -43,10 +45,37 @@ export class AuthService {
   }
 
   async signup(input: SignupInput): Promise<void> {
-    if ((await this.settings.get('auth.registrationMode')) === 'closed') {
+    // An invitation token (issue #332) lets exactly one signup through a
+    // closed registration. Claimed atomically BEFORE the account exists;
+    // rolled back if the signup fails (duplicate username), so the invitee
+    // can retry with the same link.
+    const invitation = input.invitationToken
+      ? await this.invitations.redeem(input.invitationToken)
+      : null;
+    if (input.invitationToken && !invitation) {
+      throw new BadRequestException({ code: 'token_invalid' });
+    }
+    if (!invitation && (await this.settings.get('auth.registrationMode')) === 'closed') {
       throw new ForbiddenException({ code: 'registration_closed' });
     }
-    const user = await this.users.createUser(input);
+    let user: User;
+    try {
+      user = await this.users.createUser(input);
+    } catch (error) {
+      if (invitation) await this.invitations.unredeem(invitation.id);
+      throw error;
+    }
+    if (invitation) {
+      await this.invitations.markAccepted(invitation.id, user.id);
+      await this.audit.record({
+        action: 'invitation.accepted',
+        actorId: user.id,
+        targetType: 'invitation',
+        targetId: invitation.id,
+      });
+    }
+    // The invite link proves nothing about the mailbox (it can be
+    // forwarded), so the usual verification mail still applies.
     await this.sendVerificationMail(user);
     await this.audit.record({ action: 'auth.signup', actorId: user.id });
   }

apps/api/src/auth/claim-mapping.e2e.db.test.ts

@@ -0,0 +1,272 @@
+import { createServer, type Server } from 'node:http';
+import type { AddressInfo } from 'node:net';
+
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import { SignJWT, exportJWK, generateKeyPair, type JWTPayload } from 'jose';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it, vi } from 'vitest';
+
+import { PondAccessNotifier } from '../ponds/pond-access-notifier.service';
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * IdP claim mapping (issue #217, ADR 0021): declarative `idpMapping.rules`
+ * turn ID-token claims into pond roles and the site-admin flag on every
+ * OIDC login — through the same grant-service path as manual grants (the
+ * collab revocation notify is asserted), with removal on the next login,
+ * "manual wins" precedence, and audited changes.
+ */
+describe.skipIf(!hasTestDb)('idp claim mapping (e2e, issue #217)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  let idp: Server;
+  let issuer: string;
+  const suffix = uniqueSuffix();
+
+  let signingKey: CryptoKey;
+  let publicJwk: Record<string, unknown>;
+  let nextClaims: (nonce: string) => JWTPayload;
+  let currentNonce = '';
+
+  let adminId: string;
+  let pondId: string;
+  const pondSlug = `mapped-${suffix}`;
+
+  const api = () => request(app.getHttpServer());
+
+  async function loginViaIdp(): Promise<string> {
+    const begin = await api().get('/api/v1/auth/oidc/login').expect(302);
+    const url = new URL(begin.headers.location!);
+    currentNonce = url.searchParams.get('nonce')!;
+    const stateCookie = (begin.headers['set-cookie'] as unknown as string[])
+      .find((c) => c.startsWith('dt_oidc='))!
+      .split(';')[0]!;
+    const res = await api()
+      .get(
+        `/api/v1/auth/oidc/callback?code=fake&state=${encodeURIComponent(
+          url.searchParams.get('state')!,
+        )}`,
+      )
+      .set('Cookie', stateCookie)
+      .expect(302);
+    expect(res.headers.location!).toMatch(/\/$/);
+    return sessionCookieOf(res);
+  }
+
+  function subjectClaims(groups: string[]): (nonce: string) => JWTPayload {
+    return (nonce) => ({
+      iss: issuer,
+      aud: 'dorfteich-map',
+      sub: `mapped-${suffix}`,
+      nonce,
+      email: `mapped-${suffix}@idp.example`,
+      email_verified: true,
+      preferred_username: `mapped-${suffix}`,
+      groups,
+    });
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    let signingPublic: CryptoKey;
+    ({ privateKey: signingKey, publicKey: signingPublic } = await generateKeyPair('RS256', {
+      extractable: true,
+    }));
+    publicJwk = { ...(await exportJWK(signingPublic)), kid: 'map-key', alg: 'RS256' };
+
+    idp = createServer((req, res) => {
+      void (async () => {
+        res.setHeader('content-type', 'application/json');
+        if (req.url === '/.well-known/openid-configuration') {
+          res.end(
+            JSON.stringify({
+              issuer,
+              authorization_endpoint: `${issuer}/authorize`,
+              token_endpoint: `${issuer}/token`,
+              jwks_uri: `${issuer}/jwks`,
+            }),
+          );
+        } else if (req.url === '/jwks') {
+          res.end(JSON.stringify({ keys: [publicJwk] }));
+        } else if (req.url === '/token') {
+          req.resume();
+          req.on('end', () => {
+            void (async () => {
+              const now = Math.floor(Date.now() / 1000);
+              const idToken = await new SignJWT({ ...nextClaims(currentNonce) })
+                .setProtectedHeader({ alg: 'RS256', kid: 'map-key' })
+                .setIssuedAt(now)
+                .setExpirationTime(now + 300)
+                .sign(signingKey);
+              res.end(JSON.stringify({ id_token: idToken }));
+            })();
+          });
+        } else {
+          res.statusCode = 404;
+          res.end();
+        }
+      })();
+    });
+    await new Promise<void>((resolve) => idp.listen(0, '127.0.0.1', resolve));
+    issuer = `http://127.0.0.1:${(idp.address() as AddressInfo).port}`;
+
+    process.env.OIDC_ISSUER = issuer;
+    process.env.OIDC_CLIENT_ID = 'dorfteich-map';
+    app = await createTestApp();
+
+    // A pond to map into, owned by an admin user (created via the service,
+    // grants via prisma BEFORE the first permission query — test-db rule).
+    const users = app.get(UsersService);
+    const admin = await users.createUser({
+      username: `map-admin-${suffix}`,
+      email: `map-admin-${suffix}@example.test`,
+      displayName: 'Map Admin',
+      password: 'mapping admin 123',
+      locale: 'en',
+    });
+    await users.markEmailVerified(admin.id);
+    adminId = admin.id;
+    const pond = await prisma.pond.create({
+      data: { slug: pondSlug, name: 'Mapped Pond', type: 'SHARED', ownerId: adminId },
+    });
+    pondId = pond.id;
+    await prisma.roleGrant.create({
+      data: {
+        pondId,
+        subjectType: 'USER',
+        subjectId: adminId,
+        role: 'POND_ADMIN',
+        scopeType: 'POND',
+        scopeId: null,
+        effect: 'ALLOW',
+        createdBy: adminId,
+      },
+    });
+
+    await app.get(InstanceSettingsService).set(
+      'idpMapping.rules',
+      [
+        { claim: 'groups', value: 'wiki-editors', role: 'editor', pondSlug },
+        { claim: 'groups', value: 'wiki-admins', role: 'site_admin' },
+      ],
+      adminId,
+    );
+  });
+
+  afterAll(async () => {
+    delete process.env.OIDC_ISSUER;
+    delete process.env.OIDC_CLIENT_ID;
+    await new Promise<void>((resolve) => idp.close(() => resolve()));
+    await prisma.instanceSetting.deleteMany({ where: { key: 'idpMapping.rules' } });
+    await prisma.userIdentity.deleteMany({ where: { provider: `oidc:${issuer}` } });
+    await prisma.roleGrant.deleteMany({ where: { pondId } });
+    await prisma.page.deleteMany({
+      where: { pond: { owner: { username: { contains: suffix } } } },
+    });
+    await prisma.roleGrant.deleteMany({
+      where: { pond: { owner: { username: { contains: suffix } } } },
+    });
+    await prisma.pond.deleteMany({ where: { owner: { username: { contains: suffix } } } });
+    await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('grants the mapped pond role on login and access actually works', async () => {
+    nextClaims = subjectClaims(['wiki-editors']);
+    const session = await loginViaIdp();
+
+    const grant = await prisma.roleGrant.findFirst({
+      where: { pondId, subjectType: 'USER', origin: 'idp' },
+    });
+    expect(grant).toMatchObject({ role: 'EDITOR', effect: 'ALLOW' });
+
+    // The permission model actually honours it (no raw-row bypass).
+    const pages = await api()
+      .get(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', session)
+      .expect(200);
+    expect(Array.isArray(pages.body)).toBe(true);
+
+    const audit = await prisma.auditEntry.findFirst({
+      where: { action: 'grant.created', targetId: pondId },
+      orderBy: { at: 'desc' },
+    });
+    expect(audit?.details).toMatchObject({ origin: 'idp_mapping' });
+  });
+
+  it('revokes the mapped grant on the next login without the claim — via the revocation path', async () => {
+    const notifier = app.get(PondAccessNotifier);
+    const notifySpy = vi.spyOn(notifier, 'notifyAccessChanged');
+    nextClaims = subjectClaims([]);
+    const session = await loginViaIdp();
+    try {
+      expect(await prisma.roleGrant.findFirst({ where: { pondId, origin: 'idp' } })).toBeNull();
+      // The removal travelled through the grant service: the collab
+      // revocation notify fired for this pond (the pg_notify access
+      // listener terminates live sessions — that path's own tests cover
+      // the socket close).
+      expect(notifySpy.mock.calls.some(([id]) => id === pondId)).toBe(true);
+      // …and the pond is out of reach again (404: existence hidden).
+      await api().get(`/api/v1/ponds/${pondId}/pages`).set('Cookie', session).expect(404);
+    } finally {
+      notifySpy.mockRestore();
+    }
+  });
+
+  it('never touches a manual grant, and re-creating over one is skipped (manual wins)', async () => {
+    const user = await prisma.user.findUnique({
+      where: { email: `mapped-${suffix}@idp.example` },
+    });
+    // A manual reader grant made by the pond admin.
+    await prisma.roleGrant.create({
+      data: {
+        pondId,
+        subjectType: 'USER',
+        subjectId: user!.id,
+        role: 'READER',
+        scopeType: 'POND',
+        scopeId: null,
+        effect: 'ALLOW',
+        createdBy: adminId,
+        origin: 'manual',
+      },
+    });
+
+    // Login without any mapped claim: the manual grant survives.
+    nextClaims = subjectClaims([]);
+    await loginViaIdp();
+    const manual = await prisma.roleGrant.findFirst({
+      where: { pondId, subjectId: user!.id, origin: 'manual' },
+    });
+    expect(manual).not.toBeNull();
+    expect(manual!.role).toBe('READER');
+  });
+
+  it('maps and revokes the site-admin flag — but never demotes a hand-promoted admin', async () => {
+    nextClaims = subjectClaims(['wiki-admins']);
+    await loginViaIdp();
+    let user = await prisma.user.findUnique({ where: { email: `mapped-${suffix}@idp.example` } });
+    expect(user).toMatchObject({ isSiteAdmin: true, isSiteAdminManaged: true });
+
+    nextClaims = subjectClaims([]);
+    await loginViaIdp();
+    user = await prisma.user.findUnique({ where: { email: `mapped-${suffix}@idp.example` } });
+    expect(user).toMatchObject({ isSiteAdmin: false, isSiteAdminManaged: false });
+
+    // Hand-promoted (managed=false): a claimless login must not demote.
+    await prisma.user.update({
+      where: { id: user!.id },
+      data: { isSiteAdmin: true, isSiteAdminManaged: false },
+    });
+    nextClaims = subjectClaims([]);
+    await loginViaIdp();
+    user = await prisma.user.findUnique({ where: { email: `mapped-${suffix}@idp.example` } });
+    expect(user!.isSiteAdmin).toBe(true);
+  });
+});

apps/api/src/auth/claim-mapping.service.ts

@@ -0,0 +1,161 @@
+import { Injectable } from '@nestjs/common';
+import { User } from '@prisma/client';
+import type { JWTPayload } from 'jose';
+import { PinoLogger } from 'nestjs-pino';
+
+import { AuditService } from '../audit/audit.service';
+import { GrantsService } from '../grants/grants.service';
+import { PrismaService } from '../prisma/prisma.service';
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+
+/**
+ * IdP claim mapping (issue #217, ADR 0021): on every OIDC login the
+ * declarative rules in `idpMapping.rules` are evaluated against the ID
+ * token's claims and reconciled against the user's MAPPING-OWNED state:
+ *
+ * - Pond grants are created and revoked through {@link GrantsService} —
+ *   the same path as manual grants, so the permission cache is
+ *   invalidated and live collab sessions are revalidated
+ *   (`notifyAccessChanged` → the collab access listener) exactly as on a
+ *   manual change. No raw row writes.
+ * - The mapping only ever touches rows with `origin = 'idp'` and only
+ *   demotes a site admin whose flag it itself set
+ *   (`isSiteAdminManaged`) — **manual wins**: hand-made grants and
+ *   hand-promoted admins are never revoked by a missing claim.
+ * - Every change is audited (grant.created/grant.deleted with
+ *   `origin: idp_mapping`; user.site_admin_set with the same marker).
+ *
+ * Reconciliation happens at login because that is when fresh claims
+ * exist; between logins the leaver case is the IdP's (disable there =
+ * no new login) plus the operator's account-disable flag.
+ */
+@Injectable()
+export class ClaimMappingService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly grants: GrantsService,
+    private readonly settings: InstanceSettingsService,
+    private readonly audit: AuditService,
+    private readonly logger: PinoLogger,
+  ) {
+    this.logger.setContext(ClaimMappingService.name);
+  }
+
+  async apply(user: User, payload: JWTPayload): Promise<void> {
+    const rules = await this.settings.get('idpMapping.rules');
+    if (rules.length === 0) return;
+
+    const matched = rules.filter((rule) => claimMatches(payload[rule.claim], rule.value));
+
+    await this.reconcileSiteAdmin(
+      user,
+      matched.some((rule) => rule.role === 'site_admin'),
+    );
+
+    // Desired pond grants, resolved slug → id (unknown slugs are a
+    // configuration error: logged, never fatal for the login).
+    const desired = new Map<string, 'pond_admin' | 'editor' | 'reader'>();
+    for (const rule of matched) {
+      if (rule.role === 'site_admin') continue;
+      const pond = await this.prisma.pond.findFirst({
+        where: { slug: rule.pondSlug!, deletedAt: null },
+        select: { id: true },
+      });
+      if (!pond) {
+        this.logger.warn({ pondSlug: rule.pondSlug }, 'idp mapping: unknown pond slug');
+        continue;
+      }
+      // Multiple rules for one pond: the strongest role wins.
+      const current = desired.get(pond.id);
+      if (!current || rank(rule.role) > rank(current)) desired.set(pond.id, rule.role);
+    }
+
+    const existing = await this.prisma.roleGrant.findMany({
+      where: { subjectType: 'USER', subjectId: user.id, origin: 'idp' },
+    });
+
+    for (const grant of existing) {
+      const wanted = desired.get(grant.pondId);
+      if (wanted && toDbRole(wanted) === grant.role) {
+        desired.delete(grant.pondId); // already in place
+        continue;
+      }
+      try {
+        await this.grants.deleteGrant(user, grant.pondId, grant.id, { origin: 'idp' });
+      } catch (error) {
+        // E.g. the last-Pond-Admin protection: the grant stays, the login
+        // proceeds — an operator decision is needed, not a lockout.
+        this.logger.warn(
+          { grantId: grant.id, pondId: grant.pondId, err: error },
+          'idp mapping: grant revocation refused',
+        );
+      }
+    }
+
+    for (const [pondId, role] of desired) {
+      try {
+        await this.grants.createGrant(
+          user,
+          pondId,
+          {
+            subjectType: 'user',
+            subjectId: user.id,
+            role,
+            scopeType: 'pond',
+            scopeId: null,
+            effect: 'allow',
+          },
+          { origin: 'idp' },
+        );
+      } catch (error) {
+        // A colliding MANUAL grant (grant_exists) is fine — manual wins,
+        // the mapping never replaces it with an owned copy.
+        this.logger.warn({ pondId, role, err: error }, 'idp mapping: grant creation skipped');
+      }
+    }
+  }
+
+  private async reconcileSiteAdmin(user: User, shouldBeAdmin: boolean): Promise<void> {
+    if (shouldBeAdmin && !user.isSiteAdmin) {
+      await this.prisma.user.update({
+        where: { id: user.id },
+        data: { isSiteAdmin: true, isSiteAdminManaged: true },
+      });
+      await this.audit.record({
+        action: 'user.site_admin_set',
+        actorId: user.id,
+        targetType: 'user',
+        targetId: user.id,
+        details: { isSiteAdmin: true, origin: 'idp_mapping' },
+      });
+    } else if (!shouldBeAdmin && user.isSiteAdmin && user.isSiteAdminManaged) {
+      // Only the mapping's own promotion is revocable by a missing claim.
+      await this.prisma.user.update({
+        where: { id: user.id },
+        data: { isSiteAdmin: false, isSiteAdminManaged: false },
+      });
+      await this.audit.record({
+        action: 'user.site_admin_set',
+        actorId: user.id,
+        targetType: 'user',
+        targetId: user.id,
+        details: { isSiteAdmin: false, origin: 'idp_mapping' },
+      });
+    }
+  }
+}
+
+/** A claim matches when it equals the value or, as an array, contains it. */
+function claimMatches(claim: unknown, value: string): boolean {
+  if (Array.isArray(claim)) return claim.some((entry) => String(entry) === value);
+  if (claim === undefined || claim === null) return false;
+  return String(claim) === value;
+}
+
+function rank(role: 'pond_admin' | 'editor' | 'reader'): number {
+  return role === 'pond_admin' ? 3 : role === 'editor' ? 2 : 1;
+}
+
+function toDbRole(role: 'pond_admin' | 'editor' | 'reader'): 'POND_ADMIN' | 'EDITOR' | 'READER' {
+  return role === 'pond_admin' ? 'POND_ADMIN' : role === 'editor' ? 'EDITOR' : 'READER';
+}

apps/api/src/auth/csrf.e2e.db.test.ts

@@ -0,0 +1,178 @@
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+import { SUPPRESS_ORIGIN_HEADER, createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * CSRF origin check, fail closed (issue #189): a cookie-carrying mutation
+ * without `Origin` and `Referer` is rejected exactly like a mismatch, and
+ * the exception for non-browser clients is structural — PAT/bearer requests
+ * carry no cookie and never reach the check. Cookie-authenticated requests
+ * never benefit from any header-based bypass.
+ */
+describe.skipIf(!hasTestDb)('csrf origin check (e2e, issue #189)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const password = 'csrf fail closed pass 1';
+  const ids: Record<string, string> = {};
+  const cookies: Record<string, string> = {};
+  let pondId: string;
+  let pondSlug: string;
+  let patToken: string;
+
+  const api = () => request(app.getHttpServer());
+
+  async function makeUser(handle: string): Promise<void> {
+    const users = app.get(UsersService);
+    const username = `csrf-${handle}-${suffix}`;
+    const user = await users.createUser({
+      username,
+      email: `${username}@example.org`,
+      displayName: `Csrf ${handle}`,
+      password,
+      locale: 'en',
+    });
+    await users.markEmailVerified(user.id);
+    ids[handle] = user.id;
+    cookies[handle] = sessionCookieOf(
+      await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: username, password })
+        .expect(200),
+    );
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    app = await createTestApp();
+    for (const handle of ['owner', 'siteadmin']) {
+      await makeUser(handle);
+    }
+    await prisma.user.update({ where: { id: ids.siteadmin! }, data: { isSiteAdmin: true } });
+    // Per-user quota override, never the instance default (shared database).
+    await api()
+      .put(`/api/v1/admin/quotas/user/${ids.owner!}/additional_ponds`)
+      .set('Cookie', cookies.siteadmin!)
+      .send({ value: 5 })
+      .expect(200);
+
+    // A pond opted into the public API, and a write-scope PAT for it.
+    const pond = await api()
+      .post('/api/v1/ponds')
+      .set('Cookie', cookies.owner!)
+      .send({ name: `CSRF Pond ${suffix}` })
+      .expect(201);
+    pondId = pond.body.id;
+    pondSlug = pond.body.slug;
+    await app.get(InstanceSettingsService).set('api.enabled', true, ids.siteadmin!);
+    await api()
+      .patch(`/api/v1/ponds/${pondId}`)
+      .set('Cookie', cookies.owner!)
+      .send({ apiEnabled: true })
+      .expect(200);
+    const pat = await api()
+      .post('/api/v1/users/me/api-tokens')
+      .set('Cookie', cookies.owner!)
+      .send({ name: 'csrf-write', scope: 'write' })
+      .expect(201);
+    patToken = pat.body.token;
+  });
+
+  afterAll(async () => {
+    const all = Object.values(ids);
+    await prisma.instanceSetting.deleteMany({ where: { key: 'api.enabled' } });
+    await prisma.quotaOverride.deleteMany({ where: { subjectId: { in: all } } });
+    await prisma.auditEntry.deleteMany({ where: { actorId: { in: all } } });
+    await prisma.apiToken.deleteMany({ where: { userId: { in: all } } });
+    const ponds = await prisma.pond.findMany({
+      where: { ownerId: { in: all } },
+      select: { id: true },
+    });
+    const pondIds = ponds.map((p) => p.id);
+    await prisma.pageVersion.deleteMany({ where: { page: { pondId: { in: pondIds } } } });
+    await prisma.page.deleteMany({ where: { pondId: { in: pondIds } } });
+    await prisma.roleGrant.deleteMany({ where: { pondId: { in: pondIds } } });
+    await prisma.pondUsage.deleteMany({ where: { pondId: { in: pondIds } } });
+    await prisma.pond.deleteMany({ where: { id: { in: pondIds } } });
+    await prisma.session.deleteMany({ where: { userId: { in: all } } });
+    await prisma.userIdentity.deleteMany({ where: { userId: { in: all } } });
+    await prisma.rateLimit.deleteMany({});
+    await prisma.user.deleteMany({ where: { id: { in: all } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('rejects a cookie mutation that sends neither Origin nor Referer', async () => {
+    const res = await api()
+      .patch(`/api/v1/ponds/${pondId}`)
+      .set('Cookie', cookies.owner!)
+      .set(SUPPRESS_ORIGIN_HEADER, '1')
+      .send({ name: `CSRF Pond ${suffix}` })
+      .expect(403);
+    expect(res.body.code).toBe('csrf_origin_mismatch');
+  });
+
+  it('rejects a cookie mutation from a mismatching origin (kept behaviour)', async () => {
+    const res = await api()
+      .patch(`/api/v1/ponds/${pondId}`)
+      .set('Cookie', cookies.owner!)
+      .set('Origin', 'https://evil.example')
+      .send({ name: `CSRF Pond ${suffix}` })
+      .expect(403);
+    expect(res.body.code).toBe('csrf_origin_mismatch');
+  });
+
+  it('rejects a cookie mutation with an unparsable Origin instead of erroring', async () => {
+    const res = await api()
+      .patch(`/api/v1/ponds/${pondId}`)
+      .set('Cookie', cookies.owner!)
+      .set('Origin', 'not a url')
+      .send({ name: `CSRF Pond ${suffix}` })
+      .expect(403);
+    expect(res.body.code).toBe('csrf_origin_mismatch');
+  });
+
+  it('accepts a cookie mutation from the matching origin', async () => {
+    await api()
+      .patch(`/api/v1/ponds/${pondId}`)
+      .set('Cookie', cookies.owner!)
+      .send({ name: `CSRF Pond ${suffix}` })
+      .expect(200);
+  });
+
+  it('leaves cookie reads untouched — the check binds to mutations', async () => {
+    await api()
+      .get('/api/v1/auth/me')
+      .set('Cookie', cookies.owner!)
+      .set(SUPPRESS_ORIGIN_HEADER, '1')
+      .expect(200);
+  });
+
+  it('lets a PAT mutation through without either header — no cookie, no check', async () => {
+    await api()
+      .post(`/api/public/v1/ponds/${pondSlug}/pages`)
+      .set('Authorization', `Bearer ${patToken}`)
+      .set(SUPPRESS_ORIGIN_HEADER, '1')
+      .send({ title: `CSRF PAT page ${suffix}` })
+      .expect(201);
+  });
+
+  it('enforces the check when a request carries both cookie and bearer token', async () => {
+    // Cookie-authenticated requests never benefit from the bearer exception.
+    const res = await api()
+      .patch(`/api/v1/ponds/${pondId}`)
+      .set('Cookie', cookies.owner!)
+      .set('Authorization', `Bearer ${patToken}`)
+      .set(SUPPRESS_ORIGIN_HEADER, '1')
+      .send({ name: `CSRF Pond ${suffix}` })
+      .expect(403);
+    expect(res.body.code).toBe('csrf_origin_mismatch');
+  });
+});

apps/api/src/auth/local-auth-switch.e2e.db.test.ts

@@ -0,0 +1,157 @@
+import 'reflect-metadata';
+
+import { INestApplication } from '@nestjs/common';
+import { PATH_METADATA } from '@nestjs/common/constants';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+import { LOCAL_CREDENTIAL_KEY } from './auth.guard';
+import { AuthController } from './auth.controller';
+import { OidcController } from './oidc.controller';
+import { SessionsService } from './sessions.service';
+
+/**
+ * The hard local-auth switch (issue #216, ADR 0021): AUTH_LOCAL_ENABLED=false
+ * closes EVERY local credential flow with 404 — enumerated, not assumed —
+ * while sessions themselves, logout, and token issuance for
+ * externally-authenticated users keep working (the stated decision: PATs
+ * and feed tokens authorize API access under their own switches, they are
+ * not interactive sign-in). A fence asserts every auth route is either
+ * marked as a local flow or on the reviewed allowlist.
+ */
+describe.skipIf(!hasTestDb)('local-auth switch (e2e, issue #216)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+
+  /** Every local credential surface — the enumeration the issue demands. */
+  const LOCAL_ROUTES: { method: 'post'; path: string; body: Record<string, unknown> }[] = [
+    { method: 'post', path: '/api/v1/auth/login', body: { usernameOrEmail: 'x', password: 'y' } },
+    {
+      method: 'post',
+      path: '/api/v1/auth/signup',
+      body: {
+        username: `switch-${suffix}`,
+        email: `switch-${suffix}@example.test`,
+        displayName: 'x',
+        password: 'ein langes passwort 123',
+        locale: 'en',
+      },
+    },
+    { method: 'post', path: '/api/v1/auth/verify-email', body: { token: 'x' } },
+    {
+      method: 'post',
+      path: '/api/v1/auth/resend-verification',
+      body: { email: 'x@example.test' },
+    },
+    { method: 'post', path: '/api/v1/auth/forgot-password', body: { email: 'x@example.test' } },
+    {
+      method: 'post',
+      path: '/api/v1/auth/reset-password',
+      body: { token: 'x', password: 'ein langes passwort 123' },
+    },
+    {
+      method: 'post',
+      path: '/api/v1/users/me/change-password',
+      body: { currentPassword: 'x', newPassword: 'ein langes passwort 123' },
+    },
+  ];
+
+  const api = () => request(app.getHttpServer());
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    process.env.AUTH_LOCAL_ENABLED = 'false';
+    app = await createTestApp();
+  });
+
+  afterAll(async () => {
+    delete process.env.AUTH_LOCAL_ENABLED;
+    await prisma.apiToken.deleteMany({ where: { user: { username: { contains: suffix } } } });
+    await prisma.feedToken.deleteMany({ where: { user: { username: { contains: suffix } } } });
+    await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('answers 404 on every enumerated local credential route', async () => {
+    for (const route of LOCAL_ROUTES) {
+      const res = await api()[route.method](route.path).send(route.body);
+      expect(`${route.path}: ${res.status}`).toBe(`${route.path}: 404`);
+    }
+  });
+
+  it('reports local:false so the login screen hides the form', async () => {
+    const res = await api().get('/api/v1/auth/methods').expect(200);
+    expect(res.body.local).toBe(false);
+  });
+
+  it('keeps sessions, logout, and PAT/feed-token issuance working for externally-authenticated users', async () => {
+    // An externally-authenticated user is simulated by creating the session
+    // through the session service — exactly what the OIDC/proxy paths do.
+    const users = app.get(UsersService);
+    const user = await users.createUser({
+      username: `ext-${suffix}`,
+      email: `ext-${suffix}@example.test`,
+      displayName: 'External',
+      password: 'nie benutzt weil lokal aus',
+      locale: 'en',
+    });
+    await users.markEmailVerified(user.id);
+    const token = await app.get(SessionsService).create(user.id, undefined);
+    const cookie = `dt_session=${token}`;
+
+    const me = await api().get('/api/v1/auth/me').set('Cookie', cookie).expect(200);
+    expect(me.body.id).toBe(user.id);
+
+    // Stated decision (#216): token issuance is API authorization, not
+    // interactive sign-in — it stays available under its own switches.
+    await api()
+      .post('/api/v1/users/me/api-tokens')
+      .set('Cookie', cookie)
+      .send({ name: `switch-${suffix}`, scope: 'read' })
+      .expect(201);
+    await api()
+      .post('/api/v1/users/me/feed-tokens')
+      .set('Cookie', cookie)
+      .send({ name: `switch-${suffix}` })
+      .expect(201);
+
+    await api().post('/api/v1/auth/logout').set('Cookie', cookie).expect(204);
+    await api().get('/api/v1/auth/me').set('Cookie', cookie).expect(401);
+  });
+
+  it('fence: every auth route is either a marked local flow or on the reviewed allowlist', () => {
+    // Routes that must stay reachable with local auth off — reviewed here.
+    const allowlist = new Set([
+      'registration', // signup-mode discovery; harmless metadata
+      'methods', // the login screen's discovery endpoint
+      'logout', // ending a session is not a credential flow
+      'me', // session introspection
+      'login', // OidcController: IdP redirect
+      'link', // OidcController: explicit identity linking
+      'callback', // OidcController: IdP return leg
+    ]);
+    for (const controller of [AuthController, OidcController]) {
+      for (const name of Object.getOwnPropertyNames(controller.prototype)) {
+        if (name === 'constructor') continue;
+        const handler = controller.prototype[name as keyof typeof controller.prototype] as (
+          ...args: unknown[]
+        ) => unknown;
+        const path = Reflect.getMetadata(PATH_METADATA, handler) as string | undefined;
+        if (path === undefined) continue; // not a route
+        const marked = Reflect.getMetadata(LOCAL_CREDENTIAL_KEY, handler) === true;
+        expect(
+          marked || allowlist.has(path),
+          `${controller.name}.${name} (path "${path}") is neither @LocalCredentialFlow nor allowlisted`,
+        ).toBe(true);
+      }
+    }
+  });
+});

apps/api/src/auth/oidc.controller.ts

@@ -0,0 +1,106 @@
+import { Controller, Get, Query, Req, Res } from '@nestjs/common';
+import type { Response } from 'express';
+
+import { AppConfig } from '../config/app-config.service';
+import { AuthenticatedOnly } from '../permissions/permission.decorators';
+import { RateLimit } from '../rate-limit/rate-limit.guard';
+
+import { AuthedRequest, Public, setSessionCookie } from './auth.guard';
+import { OidcService } from './oidc.service';
+import { sessionAbsoluteMs } from './sessions.service';
+
+/** Carries state+nonce+PKCE verifier across the IdP round-trip — signed
+ * (purpose-derived key), HttpOnly, Lax so the top-level callback
+ * navigation still sends it, and 10 minutes short-lived. */
+const OIDC_STATE_COOKIE = 'dt_oidc';
+
+/**
+ * OIDC endpoints (issue #214, ADR 0021). Browser-navigation shaped: `login`
+ * and `link` answer 302 to the IdP, the callback lands back here and
+ * redirects into the SPA — errors become `/login?error=<code>` so the SPA
+ * can translate them.
+ */
+@AuthenticatedOnly()
+@Controller('auth/oidc')
+export class OidcController {
+  constructor(
+    private readonly oidc: OidcService,
+    private readonly config: AppConfig,
+  ) {}
+
+  private stateCookie(response: Response, value: string): void {
+    response.cookie(OIDC_STATE_COOKIE, value, {
+      httpOnly: true,
+      sameSite: 'lax',
+      secure: this.config.env.NODE_ENV === 'production',
+      maxAge: 10 * 60 * 1000,
+      path: '/',
+    });
+  }
+
+  @Public()
+  @Get('login')
+  @RateLimit({ scope: 'oidc-login', limit: 30, windowSeconds: 60 })
+  async login(@Res() response: Response): Promise<void> {
+    this.oidc.assertEnabled();
+    const { url, stateToken } = await this.oidc.beginLogin();
+    this.stateCookie(response, stateToken);
+    response.redirect(url);
+  }
+
+  /** The deliberate account-linking flow (ADR 0021 §2): only a logged-in
+   * user attaches an IdP identity to their own account. */
+  @Get('link')
+  @RateLimit({ scope: 'oidc-login', limit: 30, windowSeconds: 60 })
+  async link(@Req() request: AuthedRequest, @Res() response: Response): Promise<void> {
+    this.oidc.assertEnabled();
+    const { url, stateToken } = await this.oidc.beginLogin(request.user!.id);
+    this.stateCookie(response, stateToken);
+    response.redirect(url);
+  }
+
+  @Public()
+  @Get('callback')
+  @RateLimit({ scope: 'oidc-callback', limit: 30, windowSeconds: 60 })
+  async callback(
+    @Query('code') code: string | undefined,
+    @Query('state') state: string | undefined,
+    @Query('error') idpError: string | undefined,
+    @Req() request: AuthedRequest,
+    @Res() response: Response,
+  ): Promise<void> {
+    this.oidc.assertEnabled();
+    const base = this.config.env.APP_BASE_URL;
+    response.clearCookie(OIDC_STATE_COOKIE, { path: '/' });
+    const stateToken = (request.cookies as Record<string, string> | undefined)?.[OIDC_STATE_COOKIE];
+    if (idpError || !code || !state || !stateToken) {
+      response.redirect(`${base}/login?error=oidc_cancelled`);
+      return;
+    }
+    try {
+      const result = await this.oidc.completeLogin(
+        code,
+        state,
+        stateToken,
+        request.headers['user-agent'],
+      );
+      if (result.linked) {
+        response.redirect(`${base}/settings?oidc=linked`);
+        return;
+      }
+      setSessionCookie(
+        response,
+        result.sessionToken!,
+        this.config.env.NODE_ENV === 'production',
+        sessionAbsoluteMs(this.config.env),
+      );
+      response.redirect(`${base}/`);
+    } catch (error) {
+      const code_ =
+        typeof (error as { response?: { code?: string } })?.response?.code === 'string'
+          ? (error as { response: { code: string } }).response.code
+          : 'oidc_failed';
+      response.redirect(`${base}/login?error=${encodeURIComponent(code_)}`);
+    }
+  }
+}

apps/api/src/auth/oidc.e2e.db.test.ts

@@ -0,0 +1,351 @@
+import { createServer, type Server } from 'node:http';
+import type { AddressInfo } from 'node:net';
+
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import { SignJWT, exportJWK, generateKeyPair, type JWTPayload } from 'jose';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * OIDC Authorization Code + PKCE against a local fake IdP (issue #214,
+ * ADR 0021): discovery, JWKS-validated ID tokens, state/nonce binding, PKCE
+ * verifier at the token endpoint, JIT account creation, the documented
+ * refusal to link silently by e-mail, and the explicit link flow. The fake
+ * IdP is protocol-shaped exactly like Keycloak's endpoints — the Keycloak
+ * verification itself is a manual procedure (security.md §External
+ * authentication).
+ */
+describe.skipIf(!hasTestDb)('oidc login (e2e, issue #214)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  let idp: Server;
+  let issuer: string;
+  const suffix = uniqueSuffix();
+
+  let signingKey: CryptoKey;
+  let publicJwk: Record<string, unknown>;
+  let wrongKey: CryptoKey;
+  /** What the fake token endpoint returns next (set per test). */
+  let nextIdToken: (() => Promise<string>) | null = null;
+  /** The last body the token endpoint received (PKCE assertions). */
+  let lastTokenRequest: URLSearchParams | null = null;
+
+  const api = () => request(app.getHttpServer());
+
+  async function mintIdToken(
+    claims: JWTPayload,
+    options: { key?: CryptoKey; expired?: boolean } = {},
+  ): Promise<string> {
+    const now = Math.floor(Date.now() / 1000);
+    return new SignJWT({ ...claims })
+      .setProtectedHeader({ alg: 'RS256', kid: 'test-key' })
+      .setIssuedAt(options.expired ? now - 7200 : now)
+      .setExpirationTime(options.expired ? now - 3600 : now + 300)
+      .sign(options.key ?? signingKey);
+  }
+
+  /** Runs /auth/oidc/login and returns the pieces the callback needs. */
+  async function beginLogin(cookie?: string) {
+    const req = api().get('/api/v1/auth/oidc/login');
+    const res = await (cookie ? req.set('Cookie', cookie) : req).expect(302);
+    const url = new URL(res.headers.location!);
+    const stateCookie = (res.headers['set-cookie'] as unknown as string[])
+      .find((c) => c.startsWith('dt_oidc='))!
+      .split(';')[0]!;
+    return {
+      state: url.searchParams.get('state')!,
+      nonce: url.searchParams.get('nonce')!,
+      challenge: url.searchParams.get('code_challenge')!,
+      stateCookie,
+      authorizeUrl: url,
+    };
+  }
+
+  async function callback(state: string, stateCookie: string) {
+    return api()
+      .get(`/api/v1/auth/oidc/callback?code=fake-code&state=${encodeURIComponent(state)}`)
+      .set('Cookie', stateCookie);
+  }
+
+  function redirectTarget(res: request.Response): string {
+    return res.headers.location!;
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    let signingPublic: CryptoKey;
+    ({ privateKey: signingKey, publicKey: signingPublic } = await generateKeyPair('RS256', {
+      extractable: true,
+    }));
+    ({ privateKey: wrongKey } = await generateKeyPair('RS256', { extractable: true }));
+    publicJwk = { ...(await exportJWK(signingPublic)), kid: 'test-key', alg: 'RS256' };
+
+    idp = createServer((req, res) => {
+      void (async () => {
+        if (req.url === '/.well-known/openid-configuration') {
+          res.setHeader('content-type', 'application/json');
+          res.end(
+            JSON.stringify({
+              issuer,
+              authorization_endpoint: `${issuer}/authorize`,
+              token_endpoint: `${issuer}/token`,
+              jwks_uri: `${issuer}/jwks`,
+            }),
+          );
+          return;
+        }
+        if (req.url === '/jwks') {
+          res.setHeader('content-type', 'application/json');
+          res.end(JSON.stringify({ keys: [publicJwk] }));
+          return;
+        }
+        if (req.url === '/token') {
+          let body = '';
+          req.on('data', (chunk) => (body += chunk));
+          req.on('end', () => {
+            void (async () => {
+              lastTokenRequest = new URLSearchParams(body);
+              res.setHeader('content-type', 'application/json');
+              if (!nextIdToken) {
+                res.statusCode = 400;
+                res.end(JSON.stringify({ error: 'invalid_grant' }));
+                return;
+              }
+              res.end(JSON.stringify({ id_token: await nextIdToken(), token_type: 'Bearer' }));
+            })();
+          });
+          return;
+        }
+        res.statusCode = 404;
+        res.end();
+      })();
+    });
+    await new Promise<void>((resolve) => idp.listen(0, '127.0.0.1', resolve));
+    issuer = `http://127.0.0.1:${(idp.address() as AddressInfo).port}`;
+
+    process.env.OIDC_ISSUER = issuer;
+    process.env.OIDC_CLIENT_ID = 'dorfteich-test';
+    process.env.OIDC_PROVIDER_LABEL = 'Fake IdP';
+    app = await createTestApp();
+  });
+
+  afterAll(async () => {
+    delete process.env.OIDC_ISSUER;
+    delete process.env.OIDC_CLIENT_ID;
+    delete process.env.OIDC_PROVIDER_LABEL;
+    await new Promise<void>((resolve) => idp.close(() => resolve()));
+    await prisma.userIdentity.deleteMany({ where: { provider: `oidc:${issuer}` } });
+    await prisma.page.deleteMany({
+      where: { pond: { owner: { email: { contains: `${suffix}@idp.example` } } } },
+    });
+    await prisma.roleGrant.deleteMany({
+      where: { pond: { owner: { email: { contains: `${suffix}@idp.example` } } } },
+    });
+    await prisma.pond.deleteMany({
+      where: { owner: { email: { contains: `${suffix}@idp.example` } } },
+    });
+    await prisma.user.deleteMany({ where: { email: { contains: `${suffix}@idp.example` } } });
+    await prisma.user.deleteMany({ where: { username: { contains: `local-${suffix}` } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('advertises the provider on /auth/methods', async () => {
+    const res = await api().get('/api/v1/auth/methods').expect(200);
+    expect(res.body).toEqual({ local: true, oidc: { label: 'Fake IdP' } });
+  });
+
+  it('logs in end to end: PKCE at the token endpoint, JIT user, identity, personal pond, session', async () => {
+    const { state, nonce, challenge, stateCookie, authorizeUrl } = await beginLogin();
+    expect(authorizeUrl.searchParams.get('code_challenge_method')).toBe('S256');
+    expect(authorizeUrl.searchParams.get('client_id')).toBe('dorfteich-test');
+
+    nextIdToken = () =>
+      mintIdToken({
+        iss: issuer,
+        aud: 'dorfteich-test',
+        sub: `subject-${suffix}`,
+        nonce,
+        email: `nadia-${suffix}@idp.example`,
+        email_verified: true,
+        preferred_username: `nadia-${suffix}`,
+        name: 'Nadia IdP',
+      });
+    const res = await callback(state, stateCookie);
+    expect(res.status).toBe(302);
+    expect(redirectTarget(res)).toMatch(/\/$/);
+    const session = sessionCookieOf(res);
+    expect(session).toContain('dt_session=');
+
+    // PKCE: the verifier travelled to the token endpoint and matches the
+    // challenge from the authorize redirect.
+    expect(lastTokenRequest?.get('grant_type')).toBe('authorization_code');
+    const verifier = lastTokenRequest?.get('code_verifier');
+    expect(verifier).toBeTruthy();
+    const { createHash } = await import('node:crypto');
+    expect(createHash('sha256').update(verifier!).digest('base64url')).toBe(challenge);
+
+    const user = await prisma.user.findUnique({
+      where: { email: `nadia-${suffix}@idp.example` },
+    });
+    expect(user).toMatchObject({ status: 'ACTIVE', displayName: 'Nadia IdP' });
+    const identity = await prisma.userIdentity.findUnique({
+      where: {
+        provider_subject: { provider: `oidc:${issuer}`, subject: `subject-${suffix}` },
+      },
+    });
+    expect(identity?.userId).toBe(user!.id);
+    const personal = await prisma.pond.findFirst({
+      where: { ownerId: user!.id, type: 'PERSONAL' },
+    });
+    expect(personal).not.toBeNull();
+
+    const me = await api().get('/api/v1/auth/me').set('Cookie', session).expect(200);
+    expect(me.body.email).toBe(`nadia-${suffix}@idp.example`);
+  });
+
+  it('reuses the existing account on the next login of the same subject', async () => {
+    const before = await prisma.user.count({ where: { email: { contains: `${suffix}@idp` } } });
+    const { state, nonce, stateCookie } = await beginLogin();
+    nextIdToken = () =>
+      mintIdToken({
+        iss: issuer,
+        aud: 'dorfteich-test',
+        sub: `subject-${suffix}`,
+        nonce,
+        email: `nadia-${suffix}@idp.example`,
+        email_verified: true,
+      });
+    const res = await callback(state, stateCookie);
+    expect(res.status).toBe(302);
+    expect(redirectTarget(res)).toMatch(/\/$/);
+    const after = await prisma.user.count({ where: { email: { contains: `${suffix}@idp` } } });
+    expect(after).toBe(before);
+  });
+
+  it('rejects a wrong state, a foreign nonce, a bad signature, wrong issuer/audience and an expired token', async () => {
+    // Wrong state: cookie from one round, state from nowhere.
+    const first = await beginLogin();
+    const bad = await callback('not-the-state', first.stateCookie);
+    expect(redirectTarget(bad)).toContain('error=oidc_state_invalid');
+
+    const cases: {
+      claims: (nonce: string) => JWTPayload;
+      options?: { key?: CryptoKey; expired?: boolean };
+    }[] = [
+      // Foreign nonce.
+      { claims: () => baseClaims('other-nonce') },
+      // Signature from the wrong key.
+      { claims: (n) => baseClaims(n), options: { key: wrongKey } },
+      // Wrong issuer.
+      { claims: (n) => ({ ...baseClaims(n), iss: 'https://evil.example' }) },
+      // Wrong audience.
+      { claims: (n) => ({ ...baseClaims(n), aud: 'someone-else' }) },
+      // Expired.
+      { claims: (n) => baseClaims(n), options: { expired: true } },
+    ];
+    function baseClaims(nonce: string): JWTPayload {
+      return {
+        iss: issuer,
+        aud: 'dorfteich-test',
+        sub: `reject-${suffix}`,
+        nonce,
+        email: `reject-${suffix}@idp.example`,
+        email_verified: true,
+      };
+    }
+    for (const testCase of cases) {
+      const { state, nonce, stateCookie } = await beginLogin();
+      nextIdToken = () => mintIdToken(testCase.claims(nonce), testCase.options);
+      const res = await callback(state, stateCookie);
+      expect(redirectTarget(res)).toContain('error=oidc_token_invalid');
+    }
+    // None of the rejected attempts created anything.
+    expect(
+      await prisma.user.findUnique({ where: { email: `reject-${suffix}@idp.example` } }),
+    ).toBeNull();
+  });
+
+  it('refuses to adopt an existing local account by e-mail — and links it via the explicit flow', async () => {
+    const users = app.get(UsersService);
+    const password = 'lokales konto 123';
+    const local = await users.createUser({
+      username: `local-${suffix}`,
+      email: `local-${suffix}@idp.example`,
+      displayName: 'Local User',
+      password,
+      locale: 'en',
+    });
+    await users.markEmailVerified(local.id);
+
+    // Silent adoption refused (ADR 0021 §2 — account-takeover path).
+    const attempt = await beginLogin();
+    nextIdToken = () =>
+      mintIdToken({
+        iss: issuer,
+        aud: 'dorfteich-test',
+        sub: `local-subject-${suffix}`,
+        nonce: attempt.nonce,
+        email: `local-${suffix}@idp.example`,
+        email_verified: true,
+      });
+    const refused = await callback(attempt.state, attempt.stateCookie);
+    expect(redirectTarget(refused)).toContain('error=oidc_link_required');
+
+    // The explicit link flow, from a logged-in session.
+    const login = await api()
+      .post('/api/v1/auth/login')
+      .send({ usernameOrEmail: `local-${suffix}`, password })
+      .expect(200);
+    const sessionCookie = sessionCookieOf(login);
+    const linkRes = await api()
+      .get('/api/v1/auth/oidc/link')
+      .set('Cookie', sessionCookie)
+      .expect(302);
+    const linkUrl = new URL(linkRes.headers.location!);
+    const linkState = linkUrl.searchParams.get('state')!;
+    const linkNonce = linkUrl.searchParams.get('nonce')!;
+    const linkCookie = (linkRes.headers['set-cookie'] as unknown as string[])
+      .find((c) => c.startsWith('dt_oidc='))!
+      .split(';')[0]!;
+    nextIdToken = () =>
+      mintIdToken({
+        iss: issuer,
+        aud: 'dorfteich-test',
+        sub: `local-subject-${suffix}`,
+        nonce: linkNonce,
+        email: `local-${suffix}@idp.example`,
+        email_verified: true,
+      });
+    const linked = await callback(linkState, linkCookie);
+    expect(redirectTarget(linked)).toContain('oidc=linked');
+    const identity = await prisma.userIdentity.findUnique({
+      where: {
+        provider_subject: { provider: `oidc:${issuer}`, subject: `local-subject-${suffix}` },
+      },
+    });
+    expect(identity?.userId).toBe(local.id);
+
+    // From now on the IdP login lands in the linked account.
+    const again = await beginLogin();
+    nextIdToken = () =>
+      mintIdToken({
+        iss: issuer,
+        aud: 'dorfteich-test',
+        sub: `local-subject-${suffix}`,
+        nonce: again.nonce,
+        email: `local-${suffix}@idp.example`,
+        email_verified: true,
+      });
+    const res = await callback(again.state, again.stateCookie);
+    const session = sessionCookieOf(res);
+    const me = await api().get('/api/v1/auth/me').set('Cookie', session).expect(200);
+    expect(me.body.id).toBe(local.id);
+  });
+});

apps/api/src/auth/oidc.service.ts

@@ -0,0 +1,359 @@
+import { createHash, randomBytes } from 'node:crypto';
+
+import {
+  BadRequestException,
+  ConflictException,
+  Injectable,
+  NotFoundException,
+  ServiceUnavailableException,
+} from '@nestjs/common';
+import { slugify } from '@dorfteich/shared';
+import { deriveTokenKey } from '@dorfteich/shared/token-crypto';
+import { User } from '@prisma/client';
+import { SignJWT, createRemoteJWKSet, jwtVerify, type JWTPayload } from 'jose';
+import { PinoLogger } from 'nestjs-pino';
+
+import { AuditService } from '../audit/audit.service';
+import { AppConfig } from '../config/app-config.service';
+import { PondsService } from '../ponds/ponds.service';
+import { PrismaService } from '../prisma/prisma.service';
+import { UsersService } from '../users/users.service';
+
+import { ClaimMappingService } from './claim-mapping.service';
+import { SessionsService } from './sessions.service';
+
+/** The state cookie's signed payload lives this long — ample for one
+ * round-trip to the IdP's login form. */
+const STATE_TTL_SECONDS = 10 * 60;
+
+/** Explicit asymmetric allowlist for ID-token signatures (no HS*, no
+ * `none`): Keycloak's default RS256 plus the common EC profile. */
+const ID_TOKEN_ALGORITHMS = ['RS256', 'ES256'];
+
+/** What we mint into the signed, HttpOnly state cookie before redirecting
+ * to the IdP: CSRF binding (`state`), replay binding (`nonce`), the PKCE
+ * verifier, and — for the deliberate account-linking flow — the session
+ * user the new identity must attach to. */
+interface OidcStateClaims extends JWTPayload {
+  state: string;
+  nonce: string;
+  codeVerifier: string;
+  linkUserId?: string;
+}
+
+interface DiscoveryDocument {
+  issuer: string;
+  authorization_endpoint: string;
+  token_endpoint: string;
+  jwks_uri: string;
+  end_session_endpoint?: string;
+}
+
+/**
+ * OIDC Authorization Code with PKCE (issue #214, ADR 0021). Deliberately
+ * built on `jose` (the vetted library from #188) plus `fetch` — no new
+ * dependency enters the supply chain for a security base function.
+ * Discovery-based: nothing here is Keycloak-specific; Keycloak is the
+ * reference IdP the flow is verified against (procedure in
+ * `docs/architecture/security.md` §External authentication).
+ *
+ * Identity linking follows ADR 0021 §2: `provider = "oidc:<issuer>"`,
+ * `subject` from the token. An existing local account is NEVER linked
+ * silently by e-mail — that would be an account-takeover path. Instead the
+ * login is refused with `oidc_link_required`, and the user (logged in
+ * locally) links explicitly via `GET /auth/oidc/link`.
+ */
+@Injectable()
+export class OidcService {
+  private discoveryCache: DiscoveryDocument | null = null;
+  private jwks: ReturnType<typeof createRemoteJWKSet> | null = null;
+
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly users: UsersService,
+    private readonly sessions: SessionsService,
+    private readonly ponds: PondsService,
+    private readonly claimMapping: ClaimMappingService,
+    private readonly audit: AuditService,
+    private readonly config: AppConfig,
+    private readonly logger: PinoLogger,
+  ) {
+    this.logger.setContext(OidcService.name);
+  }
+
+  /** OIDC is a deploy-level decision (ADR 0021): enabled iff issuer and
+   * client id are configured. */
+  get enabled(): boolean {
+    return Boolean(this.config.env.OIDC_ISSUER && this.config.env.OIDC_CLIENT_ID);
+  }
+
+  get providerLabel(): string {
+    return this.config.env.OIDC_PROVIDER_LABEL;
+  }
+
+  private get issuer(): string {
+    return this.config.env.OIDC_ISSUER!;
+  }
+
+  private get clientId(): string {
+    return this.config.env.OIDC_CLIENT_ID!;
+  }
+
+  private get redirectUri(): string {
+    return `${this.config.env.APP_BASE_URL}/api/v1/auth/oidc/callback`;
+  }
+
+  /** The identity provider key: one issuer, one provider namespace. */
+  private get provider(): string {
+    return `oidc:${this.issuer}`;
+  }
+
+  assertEnabled(): void {
+    // 404, not 403: consistent with the instance switches (`api.enabled`
+    // et al.) — an unconfigured surface hides its existence.
+    if (!this.enabled) throw new NotFoundException();
+  }
+
+  private async discover(): Promise<DiscoveryDocument> {
+    if (this.discoveryCache) return this.discoveryCache;
+    const url = `${this.issuer.replace(/\/$/, '')}/.well-known/openid-configuration`;
+    const response = await fetch(url).catch(() => null);
+    if (!response?.ok) {
+      throw new ServiceUnavailableException({ code: 'oidc_discovery_failed' });
+    }
+    const doc = (await response.json()) as DiscoveryDocument;
+    if (doc.issuer !== this.issuer) {
+      // RFC 8414 §3.3: the advertised issuer must match the configured one.
+      throw new ServiceUnavailableException({ code: 'oidc_discovery_failed' });
+    }
+    this.discoveryCache = doc;
+    this.jwks = createRemoteJWKSet(new URL(doc.jwks_uri));
+    return doc;
+  }
+
+  /** Builds the IdP redirect plus the signed state-cookie value. */
+  async beginLogin(linkUserId?: string): Promise<{ url: string; stateToken: string }> {
+    const doc = await this.discover();
+    const state = randomBytes(24).toString('base64url');
+    const nonce = randomBytes(24).toString('base64url');
+    const codeVerifier = randomBytes(48).toString('base64url');
+    const challenge = createHash('sha256').update(codeVerifier).digest('base64url');
+
+    const url = new URL(doc.authorization_endpoint);
+    url.searchParams.set('response_type', 'code');
+    url.searchParams.set('client_id', this.clientId);
+    url.searchParams.set('redirect_uri', this.redirectUri);
+    url.searchParams.set('scope', this.config.env.OIDC_SCOPES);
+    url.searchParams.set('state', state);
+    url.searchParams.set('nonce', nonce);
+    url.searchParams.set('code_challenge', challenge);
+    url.searchParams.set('code_challenge_method', 'S256');
+
+    const now = Math.floor(Date.now() / 1000);
+    const claims: OidcStateClaims = { state, nonce, codeVerifier };
+    if (linkUserId) claims.linkUserId = linkUserId;
+    const stateToken = await new SignJWT({ ...claims })
+      .setProtectedHeader({ alg: 'HS256', typ: 'JWT' })
+      .setIssuedAt(now)
+      .setExpirationTime(now + STATE_TTL_SECONDS)
+      .sign(deriveTokenKey(this.config.env.COLLAB_TOKEN_SECRET, 'oidc-state'));
+
+    return { url: url.toString(), stateToken };
+  }
+
+  private async verifyStateToken(stateToken: string): Promise<OidcStateClaims> {
+    try {
+      const { payload } = await jwtVerify(
+        stateToken,
+        deriveTokenKey(this.config.env.COLLAB_TOKEN_SECRET, 'oidc-state'),
+        { algorithms: ['HS256'] },
+      );
+      if (typeof payload.state !== 'string' || typeof payload.nonce !== 'string') throw new Error();
+      if (typeof payload.codeVerifier !== 'string') throw new Error();
+      return payload as OidcStateClaims;
+    } catch {
+      throw new BadRequestException({ code: 'oidc_state_invalid' });
+    }
+  }
+
+  /**
+   * The callback half: state check, code exchange, ID-token validation
+   * (signature via JWKS, issuer, audience, expiry — and the nonce binding),
+   * then identity resolution. Returns the session token to set plus where
+   * the SPA should land.
+   */
+  async completeLogin(
+    code: string,
+    state: string,
+    stateToken: string,
+    userAgent: string | undefined,
+  ): Promise<{ sessionToken: string | null; linked: boolean }> {
+    const doc = await this.discover();
+    const stored = await this.verifyStateToken(stateToken);
+    if (state !== stored.state) {
+      throw new BadRequestException({ code: 'oidc_state_invalid' });
+    }
+
+    const body = new URLSearchParams({
+      grant_type: 'authorization_code',
+      code,
+      redirect_uri: this.redirectUri,
+      client_id: this.clientId,
+      code_verifier: stored.codeVerifier,
+    });
+    // Confidential client: secret via client_secret_post (Keycloak default
+    // accepts it); a public client authenticates with PKCE alone.
+    if (this.config.env.OIDC_CLIENT_SECRET) {
+      body.set('client_secret', this.config.env.OIDC_CLIENT_SECRET);
+    }
+    const tokenResponse = await fetch(doc.token_endpoint, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+      body,
+    }).catch(() => null);
+    if (!tokenResponse?.ok) {
+      this.logger.warn({ status: tokenResponse?.status }, 'oidc: code exchange failed');
+      throw new BadRequestException({ code: 'oidc_exchange_failed' });
+    }
+    const tokens = (await tokenResponse.json()) as { id_token?: string };
+    if (!tokens.id_token) throw new BadRequestException({ code: 'oidc_exchange_failed' });
+
+    let payload: JWTPayload;
+    try {
+      ({ payload } = await jwtVerify(tokens.id_token, this.jwks!, {
+        issuer: this.issuer,
+        audience: this.clientId,
+        algorithms: ID_TOKEN_ALGORITHMS,
+      }));
+    } catch (error) {
+      this.logger.warn({ err: error }, 'oidc: id token rejected');
+      throw new BadRequestException({ code: 'oidc_token_invalid' });
+    }
+    if (typeof payload.nonce !== 'string' || payload.nonce !== stored.nonce) {
+      throw new BadRequestException({ code: 'oidc_token_invalid' });
+    }
+    if (typeof payload.sub !== 'string' || payload.sub.length === 0) {
+      throw new BadRequestException({ code: 'oidc_token_invalid' });
+    }
+
+    if (stored.linkUserId) {
+      await this.linkIdentity(stored.linkUserId, payload.sub);
+      return { sessionToken: null, linked: true };
+    }
+
+    const user = await this.resolveUser(payload);
+    if (user.status === 'DISABLED') {
+      throw new BadRequestException({ code: 'account_disabled' });
+    }
+    // Claim mapping (issue #217): reconcile mapped grants and the managed
+    // site-admin flag against this login's fresh claims — before the
+    // session exists, so the first request already sees the new state.
+    await this.claimMapping.apply(user, payload);
+    const sessionToken = await this.sessions.create(user.id, userAgent);
+    await this.prisma.user.update({ where: { id: user.id }, data: { lastLoginAt: new Date() } });
+    await this.audit.record({
+      action: 'auth.login_succeeded',
+      actorId: user.id,
+      details: { provider: this.provider },
+    });
+    return { sessionToken, linked: false };
+  }
+
+  /** The deliberate linking rule (ADR 0021 §2): only an authenticated user
+   * links an IdP identity to their own account — never automatic by mail. */
+  private async linkIdentity(userId: string, subject: string): Promise<void> {
+    const existing = await this.prisma.userIdentity.findUnique({
+      where: { provider_subject: { provider: this.provider, subject } },
+    });
+    if (existing && existing.userId !== userId) {
+      throw new ConflictException({ code: 'oidc_identity_taken' });
+    }
+    if (!existing) {
+      await this.prisma.userIdentity.create({
+        data: { userId, provider: this.provider, subject },
+      });
+      await this.audit.record({
+        action: 'auth.identity_linked',
+        actorId: userId,
+        details: { provider: this.provider },
+      });
+    }
+  }
+
+  private async resolveUser(payload: JWTPayload): Promise<User> {
+    const identity = await this.prisma.userIdentity.findUnique({
+      where: { provider_subject: { provider: this.provider, subject: payload.sub! } },
+    });
+    if (identity) {
+      const user = await this.users.findById(identity.userId);
+      if (!user) throw new BadRequestException({ code: 'oidc_token_invalid' });
+      return user;
+    }
+
+    // First login of this subject: just-in-time creation. The IdP owns the
+    // account lifecycle (ADR 0021), so the account arrives ACTIVE and
+    // mail-verified — provided the IdP says the address is verified.
+    const email = typeof payload.email === 'string' ? payload.email.toLowerCase() : null;
+    if (!email) throw new BadRequestException({ code: 'oidc_email_missing' });
+    if (payload.email_verified === false) {
+      throw new BadRequestException({ code: 'oidc_email_unverified' });
+    }
+    const clash = await this.users.findByEmail(email);
+    if (clash) {
+      // The documented refusal: the local owner of this address must link
+      // explicitly (GET /auth/oidc/link) — silent adoption would be an
+      // account-takeover path (ADR 0021 §2).
+      throw new ConflictException({ code: 'oidc_link_required' });
+    }
+
+    const preferred =
+      typeof payload.preferred_username === 'string' && payload.preferred_username
+        ? payload.preferred_username
+        : email.split('@')[0]!;
+    const displayName =
+      typeof payload.name === 'string' && payload.name.trim() ? payload.name.trim() : preferred;
+    const username = await this.uniqueUsername(slugify(preferred) || 'user');
+
+    const user = await this.prisma.$transaction(async (tx) => {
+      const created = await tx.user.create({
+        data: {
+          username,
+          email,
+          displayName,
+          locale: 'en',
+          status: 'ACTIVE',
+          emailVerifiedAt: new Date(),
+        },
+      });
+      await tx.userIdentity.create({
+        data: { userId: created.id, provider: this.provider, subject: payload.sub! },
+      });
+      return created;
+    });
+    // Same invariant as e-mail verification: every active account owns a
+    // personal pond (idempotent).
+    await this.ponds.ensurePersonalPond(user);
+    await this.audit.record({
+      action: 'auth.signup',
+      actorId: user.id,
+      details: { provider: this.provider },
+    });
+    return user;
+  }
+
+  private async uniqueUsername(base: string): Promise<string> {
+    const taken = new Set(
+      (
+        await this.prisma.user.findMany({
+          where: { OR: [{ username: base }, { username: { startsWith: `${base}-` } }] },
+          select: { username: true },
+        })
+      ).map((row) => row.username),
+    );
+    if (!taken.has(base)) return base;
+    for (let n = 2; ; n += 1) {
+      const candidate = `${base}-${n}`;
+      if (!taken.has(candidate)) return candidate;
+    }
+  }
+}

apps/api/src/auth/proxy-identity.e2e.db.test.ts

@@ -0,0 +1,157 @@
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+const HEADER = 'x-auth-user';
+
+/**
+ * Trusted reverse-proxy authentication (issue #215, ADR 0021): off by
+ * default (header fully ignored), identity only from a trusted TCP peer, a
+ * spoofing peer rejected AND audited, no privilege escalation past a
+ * riding-along session cookie, and the mTLS variant mapping a forwarded
+ * certificate DN attribute.
+ */
+describe.skipIf(!hasTestDb)('trusted-proxy identity (e2e, issue #215)', () => {
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const password = 'proxy identitaet 123';
+
+  const PROXY_ENV = ['AUTH_PROXY_HEADER', 'AUTH_PROXY_TRUSTED_PEERS', 'AUTH_PROXY_MODE'] as const;
+
+  async function bootApp(env: Partial<Record<(typeof PROXY_ENV)[number], string>>) {
+    for (const key of PROXY_ENV) delete process.env[key];
+    Object.assign(process.env, env);
+    return createTestApp();
+  }
+
+  async function makeUser(app: INestApplication, handle: string) {
+    const users = app.get(UsersService);
+    const user = await users.createUser({
+      username: `${handle}-${suffix}`,
+      email: `${handle}-${suffix}@example.test`,
+      displayName: handle,
+      password,
+      locale: 'en',
+    });
+    await users.markEmailVerified(user.id);
+    return user;
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+  });
+
+  afterAll(async () => {
+    for (const key of PROXY_ENV) delete process.env[key];
+    await prisma.auditEntry.deleteMany({ where: { action: 'auth.proxy_rejected' } });
+    await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
+    await prisma.$disconnect();
+  });
+
+  it('ignores the header entirely while the feature is off', async () => {
+    const app = await bootApp({});
+    try {
+      await makeUser(app, 'off');
+      await request(app.getHttpServer())
+        .get('/api/v1/auth/me')
+        .set(HEADER, `off-${suffix}`)
+        .expect(401);
+    } finally {
+      await app.close();
+    }
+  });
+
+  it('authenticates a trusted peer, maps by username, and never escalates past a session cookie', async () => {
+    const app = await bootApp({
+      AUTH_PROXY_HEADER: HEADER,
+      AUTH_PROXY_TRUSTED_PEERS: '127.0.0.1',
+    });
+    try {
+      const alice = await makeUser(app, 'alice');
+      const bob = await makeUser(app, 'bob');
+      const api = () => request(app.getHttpServer());
+
+      const me = await api().get('/api/v1/auth/me').set(HEADER, alice.username).expect(200);
+      expect(me.body.id).toBe(alice.id);
+
+      // Unknown identity: authenticated by nobody.
+      await api().get('/api/v1/auth/me').set(HEADER, `ghost-${suffix}`).expect(401);
+
+      // A session cookie riding along never escalates beyond the header
+      // identity: bob's cookie plus alice's header acts as alice.
+      const login = await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: bob.username, password })
+        .expect(200);
+      const both = await api()
+        .get('/api/v1/auth/me')
+        .set('Cookie', sessionCookieOf(login))
+        .set(HEADER, alice.username)
+        .expect(200);
+      expect(both.body.id).toBe(alice.id);
+      // Without the header the same cookie still works normally.
+      const cookieOnly = await api()
+        .get('/api/v1/auth/me')
+        .set('Cookie', sessionCookieOf(login))
+        .expect(200);
+      expect(cookieOnly.body.id).toBe(bob.id);
+    } finally {
+      await app.close();
+    }
+  });
+
+  it('rejects and audits the header from an untrusted peer — even with a valid session', async () => {
+    const app = await bootApp({
+      AUTH_PROXY_HEADER: HEADER,
+      AUTH_PROXY_TRUSTED_PEERS: '203.0.113.9',
+    });
+    try {
+      const carol = await makeUser(app, 'carol');
+      const api = () => request(app.getHttpServer());
+      await api().get('/api/v1/auth/me').set(HEADER, carol.username).expect(403);
+      const audit = await prisma.auditEntry.findFirst({
+        where: { action: 'auth.proxy_rejected' },
+        orderBy: { at: 'desc' },
+      });
+      expect(audit?.details).toMatchObject({ header: HEADER });
+
+      const login = await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: carol.username, password })
+        .expect(200);
+      // The spoofed header poisons the request even alongside a valid
+      // cookie — rejecting is safer than guessing which identity wins.
+      await api()
+        .get('/api/v1/auth/me')
+        .set('Cookie', sessionCookieOf(login))
+        .set(HEADER, carol.username)
+        .expect(403);
+    } finally {
+      await app.close();
+    }
+  });
+
+  it('maps the configured DN attribute in mtls-dn mode', async () => {
+    const app = await bootApp({
+      AUTH_PROXY_HEADER: HEADER,
+      AUTH_PROXY_TRUSTED_PEERS: '127.0.0.1',
+      AUTH_PROXY_MODE: 'mtls-dn',
+    });
+    try {
+      const dana = await makeUser(app, 'dana');
+      const me = await request(app.getHttpServer())
+        .get('/api/v1/auth/me')
+        .set(HEADER, `CN=${dana.username},OU=unit,O=example`)
+        .expect(200);
+      expect(me.body.id).toBe(dana.id);
+    } finally {
+      await app.close();
+    }
+  });
+});

apps/api/src/auth/proxy-identity.service.ts

@@ -0,0 +1,102 @@
+import { ForbiddenException, Injectable, UnauthorizedException } from '@nestjs/common';
+import { User } from '@prisma/client';
+import { PinoLogger } from 'nestjs-pino';
+
+import { AuditService } from '../audit/audit.service';
+import { AppConfig } from '../config/app-config.service';
+import { UsersService } from '../users/users.service';
+
+import type { AuthedRequest } from './auth.guard';
+
+/**
+ * Trusted reverse-proxy authentication (issue #215, ADR 0021): the
+ * perimeter (proxy or mTLS terminator) authenticates and forwards the
+ * identity in a configured header; the application trusts that header ONLY
+ * when the request's TCP peer is on the configured allowlist.
+ *
+ * The trust boundary, stated plainly (security.md §External
+ * authentication): everything upstream of the configured peers is the
+ * operator's responsibility; the application's contribution is that the
+ * header is worthless from anywhere else — a header from an untrusted peer
+ * rejects the request outright and lands in the audit trail
+ * (`auth.proxy_rejected`), because someone is attempting a spoof.
+ *
+ * Deliberately NO just-in-time creation here: the header carries no
+ * verified e-mail, so accounts must already exist (the IdP/OIDC path or an
+ * admin creates them) and are mapped by username or e-mail — explicit
+ * configuration, never guessed.
+ */
+@Injectable()
+export class ProxyIdentityService {
+  constructor(
+    private readonly users: UsersService,
+    private readonly audit: AuditService,
+    private readonly config: AppConfig,
+    private readonly logger: PinoLogger,
+  ) {
+    this.logger.setContext(ProxyIdentityService.name);
+  }
+
+  /** Enabled only with BOTH the header name and a non-empty allowlist. */
+  get enabled(): boolean {
+    return Boolean(
+      this.config.env.AUTH_PROXY_HEADER && this.config.env.AUTH_PROXY_TRUSTED_PEERS.length > 0,
+    );
+  }
+
+  /**
+   * Resolves the request's proxy identity, or null when the feature is off
+   * or the header is absent. Throws 403 (audited) for an untrusted peer
+   * carrying the header, 401 for an unknown identity.
+   */
+  async resolve(request: AuthedRequest): Promise<User | null> {
+    if (!this.enabled) return null;
+    const headerName = this.config.env.AUTH_PROXY_HEADER!.toLowerCase();
+    const raw = request.headers[headerName];
+    const value = Array.isArray(raw) ? raw[0] : raw;
+    if (!value) return null;
+
+    const peer = normalizePeer(request.socket.remoteAddress ?? '');
+    const trusted = this.config.env.AUTH_PROXY_TRUSTED_PEERS.map(normalizePeer);
+    if (!trusted.includes(peer)) {
+      // A spoof attempt, not a misconfiguration: reject and evidence it.
+      await this.audit.record({
+        action: 'auth.proxy_rejected',
+        details: { peer, header: headerName },
+      });
+      throw new ForbiddenException({ code: 'proxy_peer_untrusted' });
+    }
+
+    const identity = this.extractIdentity(value);
+    if (!identity) throw new UnauthorizedException({ code: 'proxy_identity_unknown' });
+    const user =
+      this.config.env.AUTH_PROXY_MAP === 'email'
+        ? await this.users.findByEmail(identity)
+        : await this.users.findByUsernameOrEmail(identity);
+    if (!user || user.status !== 'ACTIVE') {
+      throw new UnauthorizedException({ code: 'proxy_identity_unknown' });
+    }
+    return user;
+  }
+
+  /** `plain`: the value is the identity. `mtls-dn`: the value is a client
+   * certificate subject DN as forwarded by the TLS terminator; the identity
+   * is the configured attribute (default CN). */
+  private extractIdentity(value: string): string | null {
+    if (this.config.env.AUTH_PROXY_MODE === 'plain') return value.trim() || null;
+    const attribute = this.config.env.AUTH_PROXY_DN_ATTRIBUTE.toLowerCase();
+    for (const part of value.split(/[,/]/)) {
+      const [key, ...rest] = part.split('=');
+      if (key?.trim().toLowerCase() === attribute) {
+        const extracted = rest.join('=').trim();
+        return extracted || null;
+      }
+    }
+    return null;
+  }
+}
+
+/** `::ffff:127.0.0.1` and `127.0.0.1` are the same peer. */
+function normalizePeer(address: string): string {
+  return address.replace(/^::ffff:/i, '').trim();
+}

apps/api/src/auth/sessions.service.db.test.ts

@@ -0,0 +1,102 @@
+import { afterAll, describe, expect, it } from 'vitest';
+
+import { AppConfig } from '../config/app-config.service';
+import { PrismaService } from '../prisma/prisma.service';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+import { SessionsService, hashSessionToken } from './sessions.service';
+
+const HOUR = 60 * 60 * 1000;
+
+/** A config stub with just the session bounds (absolute 2 h, idle 1 h). */
+function configWith(absoluteHours: number, idleHours: number): AppConfig {
+  return {
+    env: { SESSION_ABSOLUTE_HOURS: absoluteHours, SESSION_IDLE_HOURS: idleHours },
+  } as AppConfig;
+}
+
+describe.skipIf(!hasTestDb)('SessionsService bounds (database, issue #190)', () => {
+  const prisma = hasTestDb ? (createTestPrisma() as unknown as PrismaService) : null!;
+  const sessions = hasTestDb ? new SessionsService(prisma, configWith(2, 1)) : null!;
+  const suffix = uniqueSuffix();
+  let userId: string;
+
+  async function makeUser(): Promise<string> {
+    if (userId) return userId;
+    const users = new UsersService(prisma);
+    const user = await users.createUser({
+      username: `sess-${suffix}`,
+      email: `sess-${suffix}@example.org`,
+      displayName: 'Sess Test',
+      password: 'session bounds pass 1',
+      locale: 'en',
+    });
+    userId = user.id;
+    return userId;
+  }
+
+  /** Creates a session and rewrites its timestamps to simulate age. */
+  async function sessionAgedTo(expiresInMs: number, lastSeenAgoMs: number): Promise<string> {
+    const raw = await sessions.create(await makeUser(), 'test-agent');
+    await prisma.session.update({
+      where: { id: hashSessionToken(raw) },
+      data: {
+        expiresAt: new Date(Date.now() + expiresInMs),
+        lastSeenAt: new Date(Date.now() - lastSeenAgoMs),
+      },
+    });
+    return raw;
+  }
+
+  afterAll(async () => {
+    if (!hasTestDb) return;
+    await prisma.session.deleteMany({ where: { userId } });
+    await prisma.userIdentity.deleteMany({ where: { userId } });
+    await prisma.user.deleteMany({ where: { id: userId } });
+    await prisma.$disconnect();
+  });
+
+  it('sets the absolute bound at creation', async () => {
+    const raw = await sessions.create(await makeUser(), 'test-agent');
+    const row = await prisma.session.findUniqueOrThrow({ where: { id: hashSessionToken(raw) } });
+    const msLeft = row.expiresAt.getTime() - Date.now();
+    expect(msLeft).toBeGreaterThan(1.9 * HOUR);
+    expect(msLeft).toBeLessThanOrEqual(2 * HOUR);
+    await sessions.destroyByRawToken(raw);
+  });
+
+  it('rejects a session past its absolute bound and removes the row', async () => {
+    const raw = await sessionAgedTo(-1000, 0);
+    expect(await sessions.validate(raw)).toBeNull();
+    expect(await prisma.session.findUnique({ where: { id: hashSessionToken(raw) } })).toBeNull();
+  });
+
+  it('rejects a session idle past the idle bound even before its absolute bound', async () => {
+    const raw = await sessionAgedTo(HOUR, 1.5 * HOUR);
+    expect(await sessions.validate(raw)).toBeNull();
+    expect(await prisma.session.findUnique({ where: { id: hashSessionToken(raw) } })).toBeNull();
+  });
+
+  it('renews the idle bound on active use but never extends the absolute bound', async () => {
+    const raw = await sessionAgedTo(HOUR, 0.5 * HOUR);
+    const before = await prisma.session.findUniqueOrThrow({
+      where: { id: hashSessionToken(raw) },
+    });
+    expect(await sessions.validate(raw)).not.toBeNull();
+    const after = await prisma.session.findUniqueOrThrow({ where: { id: hashSessionToken(raw) } });
+    expect(after.lastSeenAt.getTime()).toBeGreaterThan(before.lastSeenAt.getTime());
+    expect(after.expiresAt.getTime()).toBe(before.expiresAt.getTime());
+    await sessions.destroyByRawToken(raw);
+  });
+
+  it('hides idle-expired sessions from the session list', async () => {
+    const live = await sessionAgedTo(HOUR, 0);
+    const idle = await sessionAgedTo(HOUR, 1.5 * HOUR);
+    const listed = await sessions.listForUser(userId);
+    const ids = listed.map((s) => s.id);
+    expect(ids).toContain(hashSessionToken(live));
+    expect(ids).not.toContain(hashSessionToken(idle));
+    await sessions.destroyByRawToken(live);
+    await sessions.destroyByRawToken(idle);
+  });
+});

apps/api/src/auth/sessions.service.ts

@@ -3,24 +3,52 @@ import { createHash, randomBytes } from 'node:crypto';
 import { Injectable } from '@nestjs/common';
 import { Session, User } from '@prisma/client';
 
-import { PrismaService } from '../prisma/prisma.service';
+import type { ApiEnv } from '@dorfteich/shared';
 
-const SESSION_TTL_MS = 30 * 24 * 60 * 60 * 1000; // sliding 30 days
-const REFRESH_AT_MOST_EVERY_MS = 60 * 60 * 1000; // avoid write storms
+import { AppConfig } from '../config/app-config.service';
+import { PrismaService } from '../prisma/prisma.service';
 
 export interface ValidatedSession {
   session: Session;
   user: User;
 }
 
+/** The absolute session bound — also the cookie `maxAge` (auth.guard.ts). */
+export function sessionAbsoluteMs(env: ApiEnv): number {
+  return env.SESSION_ABSOLUTE_HOURS * 60 * 60 * 1000;
+}
+
 /**
  * Opaque server-side sessions (ADR 0007). The cookie value is 32 random
  * bytes; the database stores only its SHA-256 hash as the row id, so a
  * database leak cannot be replayed as cookies.
+ *
+ * Two configurable bounds (issue #190): `expiresAt` is the ABSOLUTE limit,
+ * set once at creation and never extended; the IDLE limit is enforced
+ * server-side against `lastSeenAt`, which active use renews. The old
+ * sliding 30-day expiry is gone — activity keeps a session alive only up
+ * to the absolute bound.
  */
 @Injectable()
 export class SessionsService {
-  constructor(private readonly prisma: PrismaService) {}
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly config: AppConfig,
+  ) {}
+
+  private absoluteMs(): number {
+    return sessionAbsoluteMs(this.config.env);
+  }
+
+  private idleMs(): number {
+    // An idle bound above the absolute one would never fire anyway.
+    return Math.min(this.config.env.SESSION_IDLE_HOURS * 60 * 60 * 1000, this.absoluteMs());
+  }
+
+  /** `lastSeenAt` write throttle: fine-grained enough for the idle bound. */
+  private refreshAtMostEveryMs(): number {
+    return Math.min(60 * 60 * 1000, Math.floor(this.idleMs() / 10));
+  }
 
   async create(userId: string, userAgent: string | undefined): Promise<string> {
     const raw = randomBytes(32).toString('base64url');
@@ -28,7 +56,7 @@ export class SessionsService {
       data: {
         id: hashSessionToken(raw),
         userId,
-        expiresAt: new Date(Date.now() + SESSION_TTL_MS),
+        expiresAt: new Date(Date.now() + this.absoluteMs()),
         userAgent: summarizeUserAgent(userAgent),
       },
     });
@@ -40,20 +68,32 @@ export class SessionsService {
       where: { id: hashSessionToken(raw) },
       include: { user: true },
     });
-    if (!session || session.expiresAt <= new Date()) return null;
+    if (!session) return null;
+    const now = Date.now();
+    const idleExpired = now - session.lastSeenAt.getTime() >= this.idleMs();
+    if (session.expiresAt.getTime() <= now || idleExpired) {
+      // Expired either way — remove the row so the session list stays truthful.
+      await this.prisma.session.deleteMany({ where: { id: session.id } });
+      return null;
+    }
     if (session.user.status === 'DISABLED') return null;
 
-    // Sliding expiration, refreshed at most once per hour.
-    if (Date.now() - session.lastSeenAt.getTime() > REFRESH_AT_MOST_EVERY_MS) {
+    // Renew the idle bound (throttled against write storms); the absolute
+    // `expiresAt` is deliberately never touched.
+    if (now - session.lastSeenAt.getTime() > this.refreshAtMostEveryMs()) {
       await this.prisma.session.update({
         where: { id: session.id },
-        data: { lastSeenAt: new Date(), expiresAt: new Date(Date.now() + SESSION_TTL_MS) },
+        data: { lastSeenAt: new Date(now) },
       });
     }
     const { user, ...bare } = session;
     return { session: bare as Session, user };
   }
 
+  private idleCutoff(now: number): Date {
+    return new Date(now - this.idleMs());
+  }
+
   async destroyByRawToken(raw: string): Promise<void> {
     await this.prisma.session.deleteMany({ where: { id: hashSessionToken(raw) } });
   }
@@ -73,8 +113,13 @@ export class SessionsService {
   }
 
   listForUser(userId: string): Promise<Session[]> {
+    // Both bounds, so an idle-expired session never shows as active.
     return this.prisma.session.findMany({
-      where: { userId, expiresAt: { gt: new Date() } },
+      where: {
+        userId,
+        expiresAt: { gt: new Date() },
+        lastSeenAt: { gt: this.idleCutoff(Date.now()) },
+      },
       orderBy: { lastSeenAt: 'desc' },
     });
   }

apps/api/src/backup/backup-status.controller.ts

@@ -0,0 +1,27 @@
+import { Controller, Get } from '@nestjs/common';
+import type { RestoreStatusResponse } from '@dorfteich/shared';
+
+import { Public } from '../auth/auth.guard';
+import { SetupExempt } from '../setup/setup.guard';
+import { MaintenanceExempt } from './maintenance.guard';
+import { MaintenanceStateService } from './maintenance-state.service';
+
+/**
+ * The status page behind maintenance mode (issue #103): while an in-app
+ * restore runs, this is the one application endpoint that keeps answering —
+ * the SPA's maintenance screen polls it to show progress and to know when
+ * to reload. Public: everyone hitting the instance mid-restore deserves the
+ * honest answer, and the status carries nothing sensitive.
+ */
+@Controller('backup')
+export class BackupStatusController {
+  constructor(private readonly state: MaintenanceStateService) {}
+
+  @Get('restore-status')
+  @Public()
+  @SetupExempt()
+  @MaintenanceExempt()
+  restoreStatus(): RestoreStatusResponse {
+    return this.state.current() ?? { state: 'idle' };
+  }
+}

apps/api/src/backup/backup-target.service.ts

@@ -0,0 +1,106 @@
+import { Injectable } from '@nestjs/common';
+import {
+  isBackupTargetAllowed,
+  type BackupConnectionTestResult,
+  type BackupSettingsView,
+} from '@dorfteich/shared';
+import { webdavCheck, type WebDavTarget } from '@dorfteich/shared/webdav';
+
+import { AppConfig } from '../config/app-config.service';
+import { SecretStoreService } from '../config/secret-store.service';
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+
+/**
+ * The api's view of the Nextcloud backup target (issue #103): instance
+ * settings hold everything non-secret, the app password lives in the
+ * wizard-written secret store (security.md §Secrets) under the key the
+ * backup sidecar reads. This service resolves, tests, and persists the
+ * combination — it never returns the password.
+ */
+export const NEXTCLOUD_PASSWORD_SECRET_KEY = 'BACKUP_NEXTCLOUD_PASSWORD';
+
+@Injectable()
+export class BackupTargetService {
+  constructor(
+    private readonly settings: InstanceSettingsService,
+    private readonly secretStore: SecretStoreService,
+    private readonly config: AppConfig,
+  ) {}
+
+  /** Deploy-level allowlist (issue #192): empty = remote targets disabled. */
+  allowlist(): string[] {
+    return this.config.env.BACKUP_ALLOWED_TARGETS;
+  }
+
+  remoteAllowed(): boolean {
+    return this.allowlist().length > 0;
+  }
+
+  targetAllowed(target: string): boolean {
+    return isBackupTargetAllowed(this.allowlist(), target);
+  }
+
+  async settingsView(): Promise<BackupSettingsView> {
+    return {
+      localRetentionDays: await this.settings.get('backup.localRetentionDays'),
+      remoteRetentionDays: await this.settings.get('backup.remoteRetentionDays'),
+      remoteTargets: { allowed: this.remoteAllowed(), allowlist: this.allowlist() },
+      nextcloud: {
+        enabled: await this.settings.get('backup.nextcloud.enabled'),
+        baseUrl: await this.settings.get('backup.nextcloud.baseUrl'),
+        username: await this.settings.get('backup.nextcloud.username'),
+        folder: await this.settings.get('backup.nextcloud.folder'),
+        uploadSchedule: await this.settings.get('backup.nextcloud.uploadSchedule'),
+        passwordSet: Boolean(this.storedPassword()),
+      },
+    };
+  }
+
+  /**
+   * The effective WebDAV target, or null when disabled or not fully
+   * configured — the exact resolution the sidecar applies on its side.
+   */
+  async resolveTarget(): Promise<WebDavTarget | null> {
+    const view = await this.settingsView();
+    const password = this.storedPassword();
+    const { enabled, baseUrl, username, folder } = view.nextcloud;
+    if (!enabled || !baseUrl || !username || !password) return null;
+    // Policy backstop (issue #192): a configured target outside the deploy
+    // allowlist behaves like no target at all.
+    if (!this.targetAllowed(baseUrl)) return null;
+    return { baseUrl, username, password, folder };
+  }
+
+  /**
+   * Live connection test (credentials + folder, creating missing folder
+   * segments) for the admin "test connection" button. An empty password
+   * falls back to the stored one, so a saved configuration can be re-tested
+   * without re-entering the secret.
+   */
+  async testConnection(candidate: {
+    baseUrl: string;
+    username: string;
+    folder: string;
+    password?: string;
+  }): Promise<BackupConnectionTestResult> {
+    const password = candidate.password || this.storedPassword();
+    if (!password) return { ok: false, error: 'no app password provided or stored' };
+    const result = await webdavCheck({
+      baseUrl: candidate.baseUrl,
+      username: candidate.username,
+      folder: candidate.folder,
+      password,
+    });
+    return result.ok ? { ok: true } : { ok: false, error: result.error };
+  }
+
+  /** Stores a new app password; empty input keeps the current one. */
+  async storePassword(password: string): Promise<void> {
+    if (!password) return;
+    await this.secretStore.set({ [NEXTCLOUD_PASSWORD_SECRET_KEY]: password });
+  }
+
+  storedPassword(): string {
+    return this.secretStore.read()[NEXTCLOUD_PASSWORD_SECRET_KEY] ?? '';
+  }
+}

apps/api/src/backup/backup.module.ts

@@ -0,0 +1,27 @@
+import { Module } from '@nestjs/common';
+import { APP_GUARD } from '@nestjs/core';
+
+import { SettingsModule } from '../settings/settings.module';
+import { BackupStatusController } from './backup-status.controller';
+import { BackupTargetService } from './backup-target.service';
+import { MaintenanceGuard } from './maintenance.guard';
+import { MaintenanceStateService } from './maintenance-state.service';
+
+/**
+ * Backup/restore integration of the api (issue #103): the maintenance gate
+ * around in-app restores plus the Nextcloud target resolution. Imported in
+ * AppModule BEFORE SetupModule on purpose — global guards run in
+ * registration order, and mid-restore nothing (not even the setup gate's
+ * database read) should touch the database.
+ */
+@Module({
+  imports: [SettingsModule],
+  controllers: [BackupStatusController],
+  providers: [
+    BackupTargetService,
+    MaintenanceStateService,
+    { provide: APP_GUARD, useClass: MaintenanceGuard },
+  ],
+  exports: [BackupTargetService, MaintenanceStateService],
+})
+export class BackupModule {}

apps/api/src/backup/maintenance-state.service.ts

@@ -0,0 +1,116 @@
+import { existsSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+import { Injectable, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
+import {
+  RESTORE_STALE_MAX_AGE_MINUTES,
+  RESTORE_STATUS_FILE,
+  type RestoreStatus,
+} from '@dorfteich/shared';
+import { PinoLogger } from 'nestjs-pino';
+
+import { AppConfig } from '../config/app-config.service';
+
+const CACHE_TTL_MS = 1500;
+const WATCH_INTERVAL_MS = 2000;
+
+/**
+ * Mirrors the sidecar's `restore-status.json` (issue #103): while a restore
+ * is `running` the maintenance guard answers 503, and once it flips to
+ * `succeeded` this service restarts the api — the restored database
+ * invalidates every in-process cache (settings, permissions, setup state),
+ * and a fresh boot also runs `migrate deploy` for sets from older versions.
+ * Docker's `unless-stopped` policy brings the container back up.
+ *
+ * A `running` state older than {@link RESTORE_STALE_MAX_AGE_MINUTES} counts
+ * as crashed (the sidecar died before writing a final state), so the
+ * instance never stays bricked behind the gate.
+ */
+@Injectable()
+export class MaintenanceStateService implements OnModuleInit, OnModuleDestroy {
+  private cached: { status: RestoreStatus | null; readAt: number } | null = null;
+  private watcher: NodeJS.Timeout | null = null;
+  private sawRunning = false;
+  private restartScheduled = false;
+
+  constructor(
+    private readonly config: AppConfig,
+    private readonly logger: PinoLogger,
+  ) {
+    this.logger.setContext(MaintenanceStateService.name);
+  }
+
+  onModuleInit(): void {
+    if (this.config.env.NODE_ENV === 'test') return;
+    // Poll independently of traffic: the restart must also happen when no
+    // request arrives while the instance sits in maintenance.
+    this.watcher = setInterval(() => this.observe(), WATCH_INTERVAL_MS);
+    this.watcher.unref?.();
+  }
+
+  onModuleDestroy(): void {
+    if (this.watcher) clearInterval(this.watcher);
+  }
+
+  /** The current restore status (short cache — the guard reads per request). */
+  current(): RestoreStatus | null {
+    const now = Date.now();
+    if (this.cached && now - this.cached.readAt < CACHE_TTL_MS) return this.cached.status;
+    const status = this.read();
+    this.cached = { status, readAt: now };
+    return status;
+  }
+
+  /** Whether the instance is in maintenance (a fresh, running restore). */
+  isActive(): boolean {
+    const status = this.current();
+    if (!status || status.state !== 'running') return false;
+    const ageMinutes = (Date.now() - new Date(status.startedAt).getTime()) / 60_000;
+    if (!Number.isFinite(ageMinutes) || ageMinutes > RESTORE_STALE_MAX_AGE_MINUTES) {
+      return false;
+    }
+    return true;
+  }
+
+  private observe(): void {
+    this.cached = null;
+    if (this.isActive()) {
+      if (!this.sawRunning) {
+        this.sawRunning = true;
+        this.logger.warn({}, 'restore running — maintenance mode active');
+      }
+      return;
+    }
+    if (!this.sawRunning) return;
+    const status = this.current();
+    this.sawRunning = false;
+    if (status?.state === 'succeeded' && !this.restartScheduled) {
+      this.restartScheduled = true;
+      this.logger.warn(
+        { backupId: status.backupId },
+        'restore succeeded — restarting the api for a clean boot on the restored database',
+      );
+      if (this.config.env.NODE_ENV === 'production') {
+        // A short delay lets the log line flush; docker restarts the container.
+        setTimeout(() => process.exit(0), 1000).unref?.();
+      } else {
+        this.logger.warn({}, 'non-production api: restart the api process manually now');
+      }
+    } else if (status?.state === 'failed') {
+      this.logger.error(
+        { backupId: status.backupId, error: status.error },
+        'restore failed — instance left maintenance mode without restoring',
+      );
+    }
+  }
+
+  private read(): RestoreStatus | null {
+    const path = join(this.config.env.BACKUPS_DIR, RESTORE_STATUS_FILE);
+    if (!existsSync(path)) return null;
+    try {
+      return JSON.parse(readFileSync(path, 'utf8')) as RestoreStatus;
+    } catch {
+      return null;
+    }
+  }
+}

apps/api/src/backup/maintenance.guard.ts

@@ -0,0 +1,46 @@
+import {
+  CanActivate,
+  ExecutionContext,
+  Injectable,
+  ServiceUnavailableException,
+  SetMetadata,
+} from '@nestjs/common';
+import { Reflector } from '@nestjs/core';
+
+import { MaintenanceStateService } from './maintenance-state.service';
+
+const MAINTENANCE_EXEMPT_KEY = 'maintenanceExempt';
+
+/**
+ * Marks routes that stay reachable while an in-app restore runs: the health
+ * probes (monitors must keep seeing the instance) and the restore status
+ * endpoint the maintenance screen polls.
+ */
+export const MaintenanceExempt = (): MethodDecorator & ClassDecorator =>
+  SetMetadata(MAINTENANCE_EXEMPT_KEY, true);
+
+/**
+ * Global first-line guard (registered before SetupModule and AuthModule via
+ * module order): while the backup sidecar restores the database, every
+ * non-exempt route answers 503 `maintenance_mode` (issue #103) — nothing
+ * may read or write mid-restore state.
+ */
+@Injectable()
+export class MaintenanceGuard implements CanActivate {
+  constructor(
+    private readonly reflector: Reflector,
+    private readonly state: MaintenanceStateService,
+  ) {}
+
+  canActivate(context: ExecutionContext): boolean {
+    const exempt = this.reflector.getAllAndOverride<boolean>(MAINTENANCE_EXEMPT_KEY, [
+      context.getHandler(),
+      context.getClass(),
+    ]);
+    if (exempt) return true;
+    if (this.state.isActive()) {
+      throw new ServiceUnavailableException({ code: 'maintenance_mode' });
+    }
+    return true;
+  }
+}

apps/api/src/branding/branding-storage.service.ts

@@ -0,0 +1,50 @@
+import { mkdir, readFile, rm, writeFile } from 'node:fs/promises';
+import { join } from 'node:path';
+
+import { Injectable } from '@nestjs/common';
+
+import { AppConfig } from '../config/app-config.service';
+
+/**
+ * Filesystem binding for branding assets (issue #306; pond overrides #307).
+ *
+ * One flat directory of PNGs named by a caller-supplied key
+ * (`instance-logo-light`, later `pond-<id>-favicon-32`). Flat because there
+ * are a handful of files per instance and the backup archives the directory
+ * as a whole — a tree would buy nothing and cost a traversal question.
+ *
+ * The key is constrained here rather than trusted from the route: it is the
+ * only thing between a request parameter and a path.
+ */
+@Injectable()
+export class BrandingStorageService {
+  constructor(private readonly config: AppConfig) {}
+
+  /** Lowercase, digits and dashes only — no dot, so no `..`, and no slash,
+   *  so the file cannot leave the directory whatever a caller sends. */
+  private pathFor(key: string): string {
+    if (!/^[a-z0-9-]{1,120}$/.test(key)) throw new Error(`invalid branding key: ${key}`);
+    return join(this.config.env.BRANDING_DIR, `${key}.png`);
+  }
+
+  async save(key: string, bytes: Buffer): Promise<void> {
+    await mkdir(this.config.env.BRANDING_DIR, { recursive: true });
+    await writeFile(this.pathFor(key), bytes);
+  }
+
+  /** The bytes, or null when the file is absent — a missing asset is a normal
+   *  state here (nothing uploaded, or metadata and disk drifted after a
+   *  partial restore), and every caller has a fallback. */
+  async read(key: string): Promise<Buffer | null> {
+    try {
+      return await readFile(this.pathFor(key));
+    } catch {
+      return null;
+    }
+  }
+
+  /** Idempotent: removing what is not there is success. */
+  async remove(key: string): Promise<void> {
+    await rm(this.pathFor(key), { force: true });
+  }
+}

apps/api/src/branding/branding.controller.ts

@@ -0,0 +1,253 @@
+import {
+  BadRequestException,
+  Controller,
+  Delete,
+  Get,
+  NotFoundException,
+  Param,
+  Post,
+  Query,
+  Req,
+  Res,
+  UploadedFiles,
+  UseGuards,
+  UseInterceptors,
+} from '@nestjs/common';
+import { AnyFilesInterceptor } from '@nestjs/platform-express';
+import {
+  BrandingView,
+  FAVICON_SIZES,
+  FaviconSize,
+  LOGO_VARIANTS,
+  LogoVariant,
+  MAX_BRANDING_BYTES,
+  PondBranding,
+} from '@dorfteich/shared';
+import type { Response } from 'express';
+
+import { SiteAdminGuard } from '../admin/site-admin.guard';
+import { AuthedRequest, Public } from '../auth/auth.guard';
+import { RequiresPondRole } from '../permissions/permission.decorators';
+import { PrismaService } from '../prisma/prisma.service';
+import { BrandingService } from './branding.service';
+
+function parseVariant(value: unknown): LogoVariant {
+  if (!LOGO_VARIANTS.includes(value as LogoVariant)) {
+    throw new BadRequestException({ code: 'bad_request' });
+  }
+  return value as LogoVariant;
+}
+
+/**
+ * Public branding surface (issue #306).
+ *
+ * Unauthenticated by design and worth stating plainly in the admin UI: the
+ * login screen carries the branding and the browser fetches the favicon before
+ * anyone signs in, so an operator's logo IS visible to anonymous visitors.
+ */
+@Controller('branding')
+export class BrandingController {
+  constructor(private readonly branding: BrandingService) {}
+
+  @Public()
+  @Get()
+  view(): Promise<BrandingView> {
+    return this.branding.view();
+  }
+
+  @Public()
+  @Get('logo')
+  async logo(
+    @Query('variant') variant: string | undefined,
+    @Query('pond') pondId: string | undefined,
+    @Res() res: Response,
+  ): Promise<void> {
+    const wanted = parseVariant(variant ?? 'light');
+    // A pond scope serves the pond's own bytes and nothing else: the caller
+    // already resolved WHICH level applies (`resolveBranding`), so silently
+    // falling back here would mix variants across levels — exactly what #307
+    // forbids.
+    const bytes = pondId
+      ? await this.branding.pondLogoBytes(pondId, wanted)
+      : await this.branding.logoBytes(wanted);
+    // No shipped default: without a logo the app renders the instance NAME as
+    // text, so an empty answer here is the honest one.
+    if (!bytes) {
+      res.status(404).json({ code: 'not_found', message: 'no logo' });
+      return;
+    }
+    res.setHeader('Content-Type', 'image/png');
+    // The caller puts the content hash in the query string, so a given URL
+    // never changes what it points at.
+    res.setHeader('Cache-Control', 'public, max-age=31536000, immutable');
+    res.send(bytes);
+  }
+
+  @Public()
+  @Get('favicon')
+  async favicon(
+    @Query('size') size: string | undefined,
+    @Query('pond') pondId: string | undefined,
+    @Res() res: Response,
+  ): Promise<void> {
+    const wanted = Number(size ?? 32);
+    if (!(FAVICON_SIZES as readonly number[]).includes(wanted)) {
+      throw new BadRequestException({ code: 'bad_request' });
+    }
+    const pondBytes = pondId
+      ? await this.branding.pondFaviconBytes(pondId, wanted as FaviconSize)
+      : null;
+    const { bytes, uploaded } = pondBytes
+      ? { bytes: pondBytes, uploaded: true }
+      : await this.branding.faviconBytes(wanted as FaviconSize);
+    res.setHeader('Content-Type', 'image/png');
+    // The `<link rel="icon">` href is a constant in index.html, so this URL
+    // cannot carry a hash — revalidation is the only way a replaced favicon
+    // ever reaches a browser that already has one.
+    res.setHeader('Cache-Control', 'no-cache');
+    res.setHeader('ETag', `"${uploaded ? 'custom' : 'default'}-${bytes.length}"`);
+    res.send(bytes);
+  }
+}
+
+/** Site-Admin management of the instance branding (issue #306). */
+@Controller('admin/branding')
+@UseGuards(SiteAdminGuard)
+export class BrandingAdminController {
+  constructor(private readonly branding: BrandingService) {}
+
+  @Post('logo')
+  @UseInterceptors(AnyFilesInterceptor({ limits: { fileSize: MAX_BRANDING_BYTES } }))
+  async setLogo(
+    @Query('variant') variant: string | undefined,
+    @Req() request: AuthedRequest,
+    @UploadedFiles() files: Express.Multer.File[] | undefined,
+  ): Promise<BrandingView> {
+    const file = files?.find((entry) => entry.fieldname === 'file');
+    if (!file) throw new BadRequestException({ code: 'branding_file_missing' });
+    return this.branding.setLogo(request.user!, parseVariant(variant ?? 'light'), file.buffer);
+  }
+
+  @Delete('logo')
+  clearLogo(
+    @Query('variant') variant: string | undefined,
+    @Req() request: AuthedRequest,
+  ): Promise<BrandingView> {
+    return this.branding.clearLogo(request.user!, parseVariant(variant ?? 'light'));
+  }
+
+  @Post('favicon')
+  @UseInterceptors(AnyFilesInterceptor({ limits: { fileSize: MAX_BRANDING_BYTES } }))
+  async setFavicon(
+    @Req() request: AuthedRequest,
+    @UploadedFiles() files: Express.Multer.File[] | undefined,
+  ): Promise<BrandingView> {
+    // Field names are the pixel sizes the browser rendered: `png-32`, `png-180`.
+    const byField = new Map((files ?? []).map((file) => [file.fieldname, file.buffer]));
+    const collected = {} as Record<FaviconSize, Buffer>;
+    for (const size of FAVICON_SIZES) {
+      const bytes = byField.get(`png-${size}`);
+      if (!bytes) throw new BadRequestException({ code: 'branding_file_missing' });
+      collected[size] = bytes;
+    }
+    return this.branding.setFavicon(request.user!, collected);
+  }
+
+  @Delete('favicon')
+  clearFavicon(@Req() request: AuthedRequest): Promise<BrandingView> {
+    return this.branding.clearFavicon(request.user!);
+  }
+}
+
+/**
+ * Pond-level branding (issue #307). The uploader here is an ordinary Pond
+ * Admin rather than the operator, so the security rules of #306 are not
+ * relaxed by a single line: SVG refused, magic bytes checked server-side,
+ * size caps enforced, content type pinned on serving, no image parsing.
+ *
+ * 404/403 policy: a user who cannot see the pond gets 404 from the pond-role
+ * guard, one who can see but not administer it gets 403.
+ */
+@Controller('ponds/:pondId/branding')
+export class PondBrandingController {
+  constructor(
+    private readonly branding: BrandingService,
+    private readonly prisma: PrismaService,
+  ) {}
+
+  /** The pond row the quota is charged to. */
+  private async pondOf(pondId: string): Promise<{ id: string; ownerId: string }> {
+    const pond = await this.prisma.pond.findUnique({
+      where: { id: pondId },
+      select: { id: true, ownerId: true },
+    });
+    if (!pond) throw new NotFoundException();
+    return pond;
+  }
+
+  @Get()
+  @RequiresPondRole('reader', { idParam: 'pondId' })
+  view(@Param('pondId') pondId: string): Promise<PondBranding> {
+    return this.branding.pondBranding(pondId);
+  }
+
+  @Post('logo')
+  @RequiresPondRole('pond_admin', { idParam: 'pondId' })
+  @UseInterceptors(AnyFilesInterceptor({ limits: { fileSize: MAX_BRANDING_BYTES } }))
+  async setLogo(
+    @Param('pondId') pondId: string,
+    @Query('variant') variant: string | undefined,
+    @Req() request: AuthedRequest,
+    @UploadedFiles() files: Express.Multer.File[] | undefined,
+  ): Promise<PondBranding> {
+    const file = files?.find((entry) => entry.fieldname === 'file');
+    if (!file) throw new BadRequestException({ code: 'branding_file_missing' });
+    return this.branding.setPondLogo(
+      request.user!,
+      await this.pondOf(pondId),
+      parseVariant(variant ?? 'light'),
+      file.buffer,
+    );
+  }
+
+  @Delete('logo')
+  @RequiresPondRole('pond_admin', { idParam: 'pondId' })
+  async clearLogo(
+    @Param('pondId') pondId: string,
+    @Query('variant') variant: string | undefined,
+    @Req() request: AuthedRequest,
+  ): Promise<PondBranding> {
+    return this.branding.clearPondLogo(
+      request.user!,
+      await this.pondOf(pondId),
+      parseVariant(variant ?? 'light'),
+    );
+  }
+
+  @Post('favicon')
+  @RequiresPondRole('pond_admin', { idParam: 'pondId' })
+  @UseInterceptors(AnyFilesInterceptor({ limits: { fileSize: MAX_BRANDING_BYTES } }))
+  async setFavicon(
+    @Param('pondId') pondId: string,
+    @Req() request: AuthedRequest,
+    @UploadedFiles() files: Express.Multer.File[] | undefined,
+  ): Promise<PondBranding> {
+    const byField = new Map((files ?? []).map((file) => [file.fieldname, file.buffer]));
+    const collected = {} as Record<FaviconSize, Buffer>;
+    for (const size of FAVICON_SIZES) {
+      const bytes = byField.get(`png-${size}`);
+      if (!bytes) throw new BadRequestException({ code: 'branding_file_missing' });
+      collected[size] = bytes;
+    }
+    return this.branding.setPondFavicon(request.user!, await this.pondOf(pondId), collected);
+  }
+
+  @Delete('favicon')
+  @RequiresPondRole('pond_admin', { idParam: 'pondId' })
+  async clearFavicon(
+    @Param('pondId') pondId: string,
+    @Req() request: AuthedRequest,
+  ): Promise<PondBranding> {
+    return this.branding.clearPondFavicon(request.user!, await this.pondOf(pondId));
+  }
+}

apps/api/src/branding/branding.e2e.db.test.ts

@@ -0,0 +1,250 @@
+import { mkdtemp, readFile, rm } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * A real PNG of `size`×`size`, built the same way the shipped default is —
+ * the api reads the IHDR, so the header has to be genuine.
+ */
+async function png(size: number): Promise<Buffer> {
+  const { deflateSync } = await import('node:zlib');
+  const crcTable = Array.from({ length: 256 }, (_, n) => {
+    let c = n;
+    for (let k = 0; k < 8; k += 1) c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
+    return c >>> 0;
+  });
+  const crc32 = (buf: Buffer): number => {
+    let c = 0xffffffff;
+    for (const byte of buf) c = crcTable[(c ^ byte) & 0xff]! ^ (c >>> 8);
+    return (c ^ 0xffffffff) >>> 0;
+  };
+  const chunk = (type: string, data: Buffer): Buffer => {
+    const length = Buffer.alloc(4);
+    length.writeUInt32BE(data.length);
+    const body = Buffer.concat([Buffer.from(type, 'ascii'), data]);
+    const crc = Buffer.alloc(4);
+    crc.writeUInt32BE(crc32(body));
+    return Buffer.concat([length, body, crc]);
+  };
+  const ihdr = Buffer.alloc(13);
+  ihdr.writeUInt32BE(size, 0);
+  ihdr.writeUInt32BE(size, 4);
+  ihdr[8] = 8;
+  ihdr[9] = 6;
+  const raw = Buffer.alloc(size * (size * 4 + 1));
+  return Buffer.concat([
+    Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]),
+    chunk('IHDR', ihdr),
+    chunk('IDAT', deflateSync(raw)),
+    chunk('IEND', Buffer.alloc(0)),
+  ]);
+}
+
+describe.skipIf(!hasTestDb)('instance branding (e2e, issue #306)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  let brandingDir: string;
+  const suffix = uniqueSuffix();
+  const password = 'markenzeichen mit teich 1';
+  const admin = { username: `ba-${suffix}` };
+  const plain = { username: `bp-${suffix}` };
+  let adminCookie: string;
+  let plainCookie: string;
+
+  const api = () => request(app.getHttpServer());
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    // A real directory: the point is that bytes land somewhere and come back.
+    brandingDir = await mkdtemp(join(tmpdir(), 'dorfteich-branding-'));
+    process.env.BRANDING_DIR = brandingDir;
+    app = await createTestApp();
+    const users = app.get(UsersService);
+
+    const adminUser = await users.createUser({
+      username: admin.username,
+      email: `${admin.username}@example.org`,
+      displayName: `Branding Admin ${suffix}`,
+      password,
+      locale: 'en',
+    });
+    await users.markEmailVerified(adminUser.id);
+    await prisma.user.update({ where: { id: adminUser.id }, data: { isSiteAdmin: true } });
+
+    const plainUser = await users.createUser({
+      username: plain.username,
+      email: `${plain.username}@example.org`,
+      displayName: `Branding Plain ${suffix}`,
+      password,
+      locale: 'en',
+    });
+    await users.markEmailVerified(plainUser.id);
+
+    const login = async (username: string): Promise<string> =>
+      sessionCookieOf(
+        await api()
+          .post('/api/v1/auth/login')
+          .send({ usernameOrEmail: username, password })
+          .expect(200),
+      );
+    adminCookie = await login(admin.username);
+    plainCookie = await login(plain.username);
+  });
+
+  afterAll(async () => {
+    await prisma.instanceSetting.deleteMany({
+      where: { key: { in: ['instance.logo', 'instance.logoDark', 'instance.favicon'] } },
+    });
+    await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
+    await prisma.$disconnect();
+    await app.close();
+    await rm(brandingDir, { recursive: true, force: true });
+    delete process.env.BRANDING_DIR;
+  });
+
+  it('serves the shipped default favicon before anything is uploaded', async () => {
+    // The `<link rel="icon">` in index.html is a constant — this route must
+    // never 404, or the browser keeps its generic icon for good.
+    const res = await api().get('/api/v1/branding/favicon').expect(200);
+    expect(res.headers['content-type']).toContain('image/png');
+    expect(res.body.subarray(0, 8).toString('latin1')).toContain('PNG');
+  });
+
+  it('stores a logo, reports it, and serves the bytes without a session', async () => {
+    const bytes = await png(64);
+    const view = await api()
+      .post('/api/v1/admin/branding/logo?variant=light')
+      .set('Cookie', adminCookie)
+      .attach('file', bytes, 'logo.png')
+      .expect(201);
+    expect(view.body.logo).toMatchObject({ width: 64, height: 64 });
+    expect(view.body.logoDark).toBeNull();
+
+    // On disk, under the key the pond override (#307) will extend.
+    const onDisk = await readFile(join(brandingDir, 'instance-logo-light.png'));
+    expect(onDisk.length).toBe(bytes.length);
+
+    // Anonymous: the login screen carries the branding.
+    const served = await api().get('/api/v1/branding/logo?variant=light').expect(200);
+    expect(served.headers['content-type']).toContain('image/png');
+    const anon = await api().get('/api/v1/branding').expect(200);
+    expect(anon.body.logo.hash).toBe(view.body.logo.hash);
+    expect(anon.body.instanceName).toBeTruthy();
+  });
+
+  it('answers 404 for a logo variant that was never uploaded', async () => {
+    // No shipped default for the logo: without one the app renders the
+    // instance NAME, so an empty answer is the honest one.
+    await api().get('/api/v1/branding/logo?variant=dark').expect(404);
+  });
+
+  it('rejects an SVG with its own message, not a generic one', async () => {
+    const res = await api()
+      .post('/api/v1/admin/branding/logo?variant=light')
+      .set('Cookie', adminCookie)
+      .attach('file', Buffer.from('<?xml version="1.0"?><svg xmlns="..."><script/></svg>'), 'x.png')
+      .expect(400);
+    expect(res.body.code).toBe('branding_svg_rejected');
+  });
+
+  it('rejects bytes that are not a PNG at all', async () => {
+    const res = await api()
+      .post('/api/v1/admin/branding/logo?variant=light')
+      .set('Cookie', adminCookie)
+      .attach('file', Buffer.from('GIF89a and then some'), 'x.png')
+      .expect(400);
+    expect(res.body.code).toBe('branding_not_a_png');
+  });
+
+  it('rejects a logo larger than the maximum edge', async () => {
+    const res = await api()
+      .post('/api/v1/admin/branding/logo?variant=light')
+      .set('Cookie', adminCookie)
+      .attach('file', await png(600), 'x.png')
+      .expect(400);
+    expect(res.body.code).toBe('branding_image_too_large');
+  });
+
+  it('takes both favicon sizes together and serves each back', async () => {
+    await api()
+      .post('/api/v1/admin/branding/favicon')
+      .set('Cookie', adminCookie)
+      .attach('png-32', await png(32), 'f32.png')
+      .attach('png-180', await png(180), 'f180.png')
+      .expect(201);
+
+    for (const size of [32, 180]) {
+      const res = await api().get(`/api/v1/branding/favicon?size=${size}`).expect(200);
+      expect(res.body.length).toBe((await png(size)).length);
+    }
+  });
+
+  it('refuses a favicon whose bytes do not match the size they claim', async () => {
+    const res = await api()
+      .post('/api/v1/admin/branding/favicon')
+      .set('Cookie', adminCookie)
+      .attach('png-32', await png(64), 'f32.png')
+      .attach('png-180', await png(180), 'f180.png')
+      .expect(400);
+    expect(res.body.code).toBe('branding_favicon_not_square');
+  });
+
+  it('clears an asset and falls back again', async () => {
+    await api().delete('/api/v1/admin/branding/favicon').set('Cookie', adminCookie).expect(200);
+    const view = await api().get('/api/v1/branding').expect(200);
+    expect(view.body.favicon).toBeNull();
+    // Back to the shipped default rather than a 404.
+    await api().get('/api/v1/branding/favicon').expect(200);
+
+    await api()
+      .delete('/api/v1/admin/branding/logo?variant=light')
+      .set('Cookie', adminCookie)
+      .expect(200);
+    await api().get('/api/v1/branding/logo?variant=light').expect(404);
+  });
+
+  it('keeps management away from a non-admin, but not reading', async () => {
+    await api()
+      .post('/api/v1/admin/branding/logo?variant=light')
+      .set('Cookie', plainCookie)
+      .attach('file', await png(32), 'x.png')
+      .expect(403);
+    await api().delete('/api/v1/admin/branding/favicon').set('Cookie', plainCookie).expect(403);
+    await api().get('/api/v1/branding').set('Cookie', plainCookie).expect(200);
+  });
+
+  it('audits every branding change with scope, asset and direction', async () => {
+    await api()
+      .post('/api/v1/admin/branding/logo?variant=dark')
+      .set('Cookie', adminCookie)
+      .attach('file', await png(48), 'logo.png')
+      .expect(201);
+    const entry = await prisma.auditEntry.findFirst({
+      where: { action: 'branding.changed', targetId: 'instance.logoDark' },
+      orderBy: { at: 'desc' },
+    });
+    expect(entry).not.toBeNull();
+    expect(entry!.details).toMatchObject({ scope: 'instance', asset: 'logoDark', change: 'set' });
+  });
+
+  it('refuses to write branding metadata through the settings endpoint', async () => {
+    // The metadata describes bytes on disk; hand-writing it would claim an
+    // asset that is not there, so the settings PATCH does not accept it.
+    const res = await api()
+      .patch('/api/v1/admin/settings')
+      .set('Cookie', adminCookie)
+      .send({ 'instance.logo': { hash: 'deadbeefdeadbeef', width: 10, height: 10 } })
+      .expect(400);
+    expect(res.body.code).toBe('bad_request');
+  });
+});

apps/api/src/branding/branding.module.ts

@@ -0,0 +1,23 @@
+import { Module } from '@nestjs/common';
+
+import { PermissionsModule } from '../permissions/permissions.module';
+import { QuotasModule } from '../quotas/quotas.module';
+
+import {
+  BrandingAdminController,
+  BrandingController,
+  PondBrandingController,
+} from './branding.controller';
+import { BrandingStorageService } from './branding-storage.service';
+import { BrandingService } from './branding.service';
+
+/** Instance branding — logo and favicon (issue #306). Exports the services so
+ * the pond-level override (#307) can build on the same storage and the same
+ * resolution path instead of a parallel one. */
+@Module({
+  imports: [PermissionsModule, QuotasModule],
+  controllers: [BrandingController, BrandingAdminController, PondBrandingController],
+  providers: [BrandingService, BrandingStorageService],
+  exports: [BrandingService, BrandingStorageService],
+})
+export class BrandingModule {}

apps/api/src/branding/branding.service.ts

@@ -0,0 +1,380 @@
+import { createHash } from 'node:crypto';
+import { readFile } from 'node:fs/promises';
+import { join } from 'node:path';
+
+import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
+import {
+  BrandingAsset,
+  BrandingView,
+  FAVICON_SIZES,
+  FaviconSize,
+  LOGO_VARIANTS,
+  LogoVariant,
+  PondBranding,
+  pondSettingsSchema,
+  MAX_BRANDING_BYTES,
+  MAX_LOGO_EDGE,
+  hasPngMagic,
+  looksLikeSvg,
+  pngDimensions,
+} from '@dorfteich/shared';
+import { User } from '@prisma/client';
+
+import { AuditService } from '../audit/audit.service';
+import { PrismaService } from '../prisma/prisma.service';
+import { QuotaService } from '../quotas/quota.service';
+import { InstanceSettingsService } from '../settings/instance-settings.service';
+import { BrandingStorageService } from './branding-storage.service';
+
+/** The settings key each instance asset's metadata lives under. */
+const INSTANCE_KEYS = {
+  logoLight: 'instance.logo',
+  logoDark: 'instance.logoDark',
+  favicon: 'instance.favicon',
+} as const;
+
+/**
+ * Instance branding (issue #306): the logo shown at the top of the sidebar and
+ * the favicon served to the browser.
+ *
+ * The api stores and serves bytes; it never decodes them. Validation is the
+ * PNG signature, the IHDR dimensions and the size cap — see
+ * `packages/shared/src/branding.ts` for why that line is drawn there.
+ */
+@Injectable()
+export class BrandingService {
+  constructor(
+    private readonly settings: InstanceSettingsService,
+    private readonly storage: BrandingStorageService,
+    private readonly audit: AuditService,
+    private readonly prisma: PrismaService,
+    private readonly quotas: QuotaService,
+  ) {}
+
+  static logoKey(variant: LogoVariant): string {
+    return `instance-logo-${variant}`;
+  }
+
+  static faviconKey(size: FaviconSize): string {
+    return `instance-favicon-${size}`;
+  }
+
+  /** Pond assets share the directory and the naming rules (issue #307); the
+   *  pond id keeps them apart and makes purge a prefix delete. */
+  static pondLogoKey(pondId: string, variant: LogoVariant): string {
+    return `pond-${pondId}-logo-${variant}`;
+  }
+
+  static pondFaviconKey(pondId: string, size: FaviconSize): string {
+    return `pond-${pondId}-favicon-${size}`;
+  }
+
+  /** Every branding file a pond can own — the purge deletes exactly this set
+   *  (issue #307). The purge standard is absolute: after it, nothing
+   *  referencing the pond survives, rows or files. */
+  static pondKeys(pondId: string): string[] {
+    return [
+      ...LOGO_VARIANTS.map((variant) => BrandingService.pondLogoKey(pondId, variant)),
+      ...FAVICON_SIZES.map((size) => BrandingService.pondFaviconKey(pondId, size)),
+    ];
+  }
+
+  /**
+   * Rejects anything that is not a PNG within the caps, before a byte is
+   * written. SVG gets its own message: an operator who tried one deserves to
+   * learn that it is refused on purpose, not that "the file is broken".
+   */
+  private assertUsablePng(bytes: Buffer, maxEdge: number): { width: number; height: number } {
+    if (bytes.length === 0) throw new BadRequestException({ code: 'branding_file_empty' });
+    if (bytes.length > MAX_BRANDING_BYTES) {
+      throw new BadRequestException({ code: 'branding_file_too_large' });
+    }
+    if (looksLikeSvg(bytes)) throw new BadRequestException({ code: 'branding_svg_rejected' });
+    if (!hasPngMagic(bytes)) throw new BadRequestException({ code: 'branding_not_a_png' });
+    const size = pngDimensions(bytes);
+    if (!size) throw new BadRequestException({ code: 'branding_not_a_png' });
+    if (size.width > maxEdge || size.height > maxEdge) {
+      throw new BadRequestException({ code: 'branding_image_too_large' });
+    }
+    return size;
+  }
+
+  /**
+   * Reserve the pond's storage for a branding asset, releasing what the asset
+   * it replaces occupied. Doing it in that order means replacing a logo with
+   * one of the same size costs nothing — otherwise every re-upload would eat
+   * the quota again, which is how "a pond admin fills the disk with logos"
+   * happens.
+   */
+  private async chargeQuota(
+    pond: { id: string; ownerId: string },
+    bytes: number,
+    previous: BrandingAsset | null,
+  ): Promise<void> {
+    if (previous?.byteSize) await this.quotas.release(pond.id, previous.byteSize);
+    try {
+      await this.quotas.checkAndConsume(pond.id, pond.ownerId, bytes);
+    } catch (error) {
+      // Put the released reservation back: a refused upload must not leave
+      // the pond with MORE room than before.
+      if (previous?.byteSize) {
+        await this.quotas.checkAndConsume(pond.id, pond.ownerId, previous.byteSize);
+      }
+      throw error;
+    }
+  }
+
+  private assetOf(bytes: Buffer, size: { width: number; height: number }): BrandingAsset {
+    return {
+      // Short digest: it only has to change when the bytes change, and it
+      // travels in every logo URL.
+      hash: createHash('sha256').update(bytes).digest('hex').slice(0, 16),
+      byteSize: bytes.length,
+      ...size,
+    };
+  }
+
+  async view(): Promise<BrandingView> {
+    const [logo, logoDark, favicon, instanceName] = await Promise.all([
+      this.settings.get(INSTANCE_KEYS.logoLight),
+      this.settings.get(INSTANCE_KEYS.logoDark),
+      this.settings.get(INSTANCE_KEYS.favicon),
+      this.settings.get('instance.name'),
+    ]);
+    return { logo, logoDark, favicon, instanceName };
+  }
+
+  async setLogo(admin: User, variant: LogoVariant, bytes: Buffer): Promise<BrandingView> {
+    const size = this.assertUsablePng(bytes, MAX_LOGO_EDGE);
+    await this.storage.save(BrandingService.logoKey(variant), bytes);
+    await this.settings.set(
+      variant === 'dark' ? INSTANCE_KEYS.logoDark : INSTANCE_KEYS.logoLight,
+      this.assetOf(bytes, size),
+      admin.id,
+    );
+    await this.record(admin, variant === 'dark' ? 'logoDark' : 'logo', 'set');
+    return this.view();
+  }
+
+  async clearLogo(admin: User, variant: LogoVariant): Promise<BrandingView> {
+    await this.storage.remove(BrandingService.logoKey(variant));
+    await this.settings.set(
+      variant === 'dark' ? INSTANCE_KEYS.logoDark : INSTANCE_KEYS.logoLight,
+      null,
+      admin.id,
+    );
+    await this.record(admin, variant === 'dark' ? 'logoDark' : 'logo', 'cleared');
+    return this.view();
+  }
+
+  /**
+   * Both favicon sizes arrive together: the browser produced them from one
+   * source on the same canvas, and the api cannot resize. Storing them as a
+   * pair keeps the tab icon and the home-screen icon from ever showing two
+   * different images.
+   */
+  async setFavicon(admin: User, files: Record<FaviconSize, Buffer>): Promise<BrandingView> {
+    const sizes = Object.entries(files).map(([declared, bytes]) => {
+      const size = this.assertUsablePng(bytes, 512);
+      const expected = Number(declared);
+      if (size.width !== expected || size.height !== expected) {
+        throw new BadRequestException({ code: 'branding_favicon_not_square' });
+      }
+      return { expected: expected as FaviconSize, bytes, size };
+    });
+    for (const entry of sizes) {
+      await this.storage.save(BrandingService.faviconKey(entry.expected), entry.bytes);
+    }
+    // The 32px variant identifies the pair — it is what the tab shows.
+    const small = sizes.find((entry) => entry.expected === 32)!;
+    await this.settings.set(INSTANCE_KEYS.favicon, this.assetOf(small.bytes, small.size), admin.id);
+    await this.record(admin, 'favicon', 'set');
+    return this.view();
+  }
+
+  async clearFavicon(admin: User): Promise<BrandingView> {
+    await this.storage.remove(BrandingService.faviconKey(32));
+    await this.storage.remove(BrandingService.faviconKey(180));
+    await this.settings.set(INSTANCE_KEYS.favicon, null, admin.id);
+    await this.record(admin, 'favicon', 'cleared');
+    return this.view();
+  }
+
+  /** The bytes to serve for a logo variant, or null when none is stored. */
+  logoBytes(variant: LogoVariant): Promise<Buffer | null> {
+    return this.storage.read(BrandingService.logoKey(variant));
+  }
+
+  /**
+   * The favicon bytes: the uploaded one, else the shipped default. The
+   * `<link rel="icon">` in index.html is static, so this route must always
+   * answer with an image — a 404 there would leave the browser's generic
+   * icon for good.
+   */
+  async faviconBytes(size: FaviconSize): Promise<{ bytes: Buffer; uploaded: boolean }> {
+    const stored = await this.storage.read(BrandingService.faviconKey(size));
+    if (stored) return { bytes: stored, uploaded: true };
+    const bytes = await readFile(join(__dirname, '../../assets', `default-favicon-${size}.png`));
+    return { bytes, uploaded: false };
+  }
+
+  /** The pond's own branding, defaulted — one place reads the settings blob. */
+  async pondBranding(pondId: string): Promise<PondBranding> {
+    const pond = await this.prisma.pond.findUnique({
+      where: { id: pondId },
+      select: { settings: true },
+    });
+    if (!pond) throw new NotFoundException();
+    return pondSettingsSchema.parse(pond.settings ?? {}).branding;
+  }
+
+  private async writePondBranding(
+    actor: User,
+    pondId: string,
+    next: PondBranding,
+    asset: 'logo' | 'logoDark' | 'favicon',
+    change: 'set' | 'cleared',
+  ): Promise<PondBranding> {
+    const pond = await this.prisma.pond.findUniqueOrThrow({
+      where: { id: pondId },
+      select: { settings: true },
+    });
+    const settings = pondSettingsSchema.parse(pond.settings ?? {});
+    await this.prisma.pond.update({
+      where: { id: pondId },
+      data: { settings: { ...settings, branding: next } as object },
+    });
+    await this.audit.record({
+      action: 'branding.changed',
+      actorId: actor.id,
+      targetType: 'pond',
+      targetId: pondId,
+      details: { scope: 'pond', pondId, asset, change },
+    });
+    return next;
+  }
+
+  /**
+   * A pond logo, charged to the pond's storage quota (issue #307).
+   *
+   * Without the charge, branding would be a way around the quota — and
+   * replacing a logo repeatedly would let a pond admin consume disk with no
+   * ceiling. Charged BEFORE the write, like attachments, so a race never
+   * leaves bytes on the volume without a reservation; the bytes a replaced
+   * asset frees are released first, so re-uploading the same logo is free
+   * rather than cumulative.
+   */
+  async setPondLogo(
+    actor: User,
+    pond: { id: string; ownerId: string },
+    variant: LogoVariant,
+    bytes: Buffer,
+  ): Promise<PondBranding> {
+    const size = this.assertUsablePng(bytes, MAX_LOGO_EDGE);
+    const current = await this.pondBranding(pond.id);
+    const previous = variant === 'dark' ? current.logoDark : current.logo;
+    await this.chargeQuota(pond, bytes.length, previous);
+    await this.storage.save(BrandingService.pondLogoKey(pond.id, variant), bytes);
+    const asset = this.assetOf(bytes, size);
+    return this.writePondBranding(
+      actor,
+      pond.id,
+      variant === 'dark' ? { ...current, logoDark: asset } : { ...current, logo: asset },
+      variant === 'dark' ? 'logoDark' : 'logo',
+      'set',
+    );
+  }
+
+  async clearPondLogo(
+    actor: User,
+    pond: { id: string; ownerId: string },
+    variant: LogoVariant,
+  ): Promise<PondBranding> {
+    const current = await this.pondBranding(pond.id);
+    const previous = variant === 'dark' ? current.logoDark : current.logo;
+    await this.storage.remove(BrandingService.pondLogoKey(pond.id, variant));
+    if (previous?.byteSize) await this.quotas.release(pond.id, previous.byteSize);
+    return this.writePondBranding(
+      actor,
+      pond.id,
+      variant === 'dark' ? { ...current, logoDark: null } : { ...current, logo: null },
+      variant === 'dark' ? 'logoDark' : 'logo',
+      'cleared',
+    );
+  }
+
+  async setPondFavicon(
+    actor: User,
+    pond: { id: string; ownerId: string },
+    files: Record<FaviconSize, Buffer>,
+  ): Promise<PondBranding> {
+    const checked = Object.entries(files).map(([declared, bytes]) => {
+      const size = this.assertUsablePng(bytes, 512);
+      const expected = Number(declared);
+      if (size.width !== expected || size.height !== expected) {
+        throw new BadRequestException({ code: 'branding_favicon_not_square' });
+      }
+      return { expected: expected as FaviconSize, bytes, size };
+    });
+    const current = await this.pondBranding(pond.id);
+    const total = checked.reduce((sum, entry) => sum + entry.bytes.length, 0);
+    await this.chargeQuota(pond, total, current.favicon);
+    for (const entry of checked) {
+      await this.storage.save(BrandingService.pondFaviconKey(pond.id, entry.expected), entry.bytes);
+    }
+    const small = checked.find((entry) => entry.expected === 32)!;
+    // The pair is charged together, so the stored size is the pair's — that
+    // is what a later release has to give back.
+    const asset = { ...this.assetOf(small.bytes, small.size), byteSize: total };
+    return this.writePondBranding(actor, pond.id, { ...current, favicon: asset }, 'favicon', 'set');
+  }
+
+  async clearPondFavicon(
+    actor: User,
+    pond: { id: string; ownerId: string },
+  ): Promise<PondBranding> {
+    const current = await this.pondBranding(pond.id);
+    for (const size of FAVICON_SIZES) {
+      await this.storage.remove(BrandingService.pondFaviconKey(pond.id, size));
+    }
+    if (current.favicon?.byteSize) await this.quotas.release(pond.id, current.favicon.byteSize);
+    return this.writePondBranding(
+      actor,
+      pond.id,
+      { ...current, favicon: null },
+      'favicon',
+      'cleared',
+    );
+  }
+
+  /** Bytes for a pond asset — null when the pond has none at that slot, which
+   *  is what makes the caller fall back to the instance level. */
+  pondLogoBytes(pondId: string, variant: LogoVariant): Promise<Buffer | null> {
+    return this.storage.read(BrandingService.pondLogoKey(pondId, variant));
+  }
+
+  pondFaviconBytes(pondId: string, size: FaviconSize): Promise<Buffer | null> {
+    return this.storage.read(BrandingService.pondFaviconKey(pondId, size));
+  }
+
+  /** Removes every branding file of a pond (issue #307's purge obligation). */
+  async removePondAssets(pondId: string): Promise<void> {
+    for (const key of BrandingService.pondKeys(pondId)) await this.storage.remove(key);
+  }
+
+  private record(
+    admin: User,
+    asset: 'logo' | 'logoDark' | 'favicon',
+    action: 'set' | 'cleared',
+  ): Promise<unknown> {
+    // `scope` is here from the start so the pond-level change (#307) is the
+    // same event with a different scope, not a second id in the catalogue.
+    return this.audit.record({
+      action: 'branding.changed',
+      actorId: admin.id,
+      targetType: 'setting',
+      targetId: `instance.${asset}`,
+      details: { scope: 'instance', asset, change: action },
+    });
+  }
+}

apps/api/src/branding/pond-branding.e2e.db.test.ts

@@ -0,0 +1,256 @@
+import { mkdtemp, rm } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { deflateSync } from 'node:zlib';
+
+import { INestApplication } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { AuthTokensService } from '../auth/auth-tokens.service';
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import {
+  createTestPrisma,
+  deletePondsWhere,
+  grantOwnerAdmin,
+  hasTestDb,
+  uniqueSuffix,
+} from '../testing/test-db';
+import { TrashService } from '../trash/trash.service';
+import { UsersService } from '../users/users.service';
+
+import { BrandingService } from './branding.service';
+import { BrandingStorageService } from './branding-storage.service';
+
+const crcTable = Array.from({ length: 256 }, (_, n) => {
+  let c = n;
+  for (let k = 0; k < 8; k += 1) c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
+  return c >>> 0;
+});
+function crc32(buf: Buffer): number {
+  let c = 0xffffffff;
+  for (const byte of buf) c = crcTable[(c ^ byte) & 0xff]! ^ (c >>> 8);
+  return (c ^ 0xffffffff) >>> 0;
+}
+function chunk(type: string, data: Buffer): Buffer {
+  const length = Buffer.alloc(4);
+  length.writeUInt32BE(data.length);
+  const body = Buffer.concat([Buffer.from(type, 'ascii'), data]);
+  const crc = Buffer.alloc(4);
+  crc.writeUInt32BE(crc32(body));
+  return Buffer.concat([length, body, crc]);
+}
+/** A real PNG — the api reads the IHDR, so the header has to be genuine. */
+function png(size: number): Buffer {
+  const ihdr = Buffer.alloc(13);
+  ihdr.writeUInt32BE(size, 0);
+  ihdr.writeUInt32BE(size, 4);
+  ihdr[8] = 8;
+  ihdr[9] = 6;
+  return Buffer.concat([
+    Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]),
+    chunk('IHDR', ihdr),
+    chunk('IDAT', deflateSync(Buffer.alloc(size * (size * 4 + 1)))),
+    chunk('IEND', Buffer.alloc(0)),
+  ]);
+}
+
+describe.skipIf(!hasTestDb)('pond branding (e2e, issue #307)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  let storage: BrandingStorageService;
+  let brandingDir: string;
+  const suffix = uniqueSuffix();
+  const password = 'teichmarke mit eigenem logo 1';
+  const owner = { username: `pb-${suffix}` };
+  const member = { username: `pbm-${suffix}` };
+  let ownerCookie: string;
+  let memberCookie: string;
+  let pondId: string;
+
+  const api = () => request(app.getHttpServer());
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    brandingDir = await mkdtemp(join(tmpdir(), 'dorfteich-pondbranding-'));
+    process.env.BRANDING_DIR = brandingDir;
+    app = await createTestApp();
+    storage = app.get(BrandingStorageService);
+    const users = app.get(UsersService);
+    const tokens = app.get(AuthTokensService);
+    // Verification through the endpoint, not `markEmailVerified`: only this
+    // path creates the personal pond these tests brand.
+    const verify = async (userId: string): Promise<void> => {
+      await api()
+        .post('/api/v1/auth/verify-email')
+        .send({ token: await tokens.issue(userId, 'EMAIL_VERIFICATION', 600) })
+        .expect(204);
+    };
+
+    const ownerUser = await users.createUser({
+      username: owner.username,
+      email: `${owner.username}@example.org`,
+      displayName: `Pond Branding Owner ${suffix}`,
+      password,
+      locale: 'en',
+    });
+    await verify(ownerUser.id);
+    const memberUser = await users.createUser({
+      username: member.username,
+      email: `${member.username}@example.org`,
+      displayName: `Pond Branding Member ${suffix}`,
+      password,
+      locale: 'en',
+    });
+    await verify(memberUser.id);
+
+    const login = async (username: string): Promise<string> =>
+      sessionCookieOf(
+        await api()
+          .post('/api/v1/auth/login')
+          .send({ usernameOrEmail: username, password })
+          .expect(200),
+      );
+    ownerCookie = await login(owner.username);
+    memberCookie = await login(member.username);
+
+    pondId = (
+      await prisma.pond.findFirstOrThrow({ where: { ownerId: ownerUser.id, type: 'PERSONAL' } })
+    ).id;
+    // A reader on the same pond: may see it, may not administer it. Through
+    // the API, not a raw row — the permission cache would not see the row
+    // (the documented rule for grants in tests).
+    await api()
+      .post(`/api/v1/ponds/${pondId}/grants`)
+      .set('Cookie', ownerCookie)
+      .send({
+        subjectType: 'user',
+        subjectId: memberUser.id,
+        role: 'reader',
+        scopeType: 'pond',
+        effect: 'allow',
+      })
+      .expect(201);
+  });
+
+  afterAll(async () => {
+    await prisma.roleGrant.deleteMany({
+      where: { pond: { owner: { username: { contains: suffix } } } },
+    });
+    await deletePondsWhere(prisma, { owner: { username: { contains: suffix } } });
+    await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
+    await prisma.$disconnect();
+    await app.close();
+    await rm(brandingDir, { recursive: true, force: true });
+    delete process.env.BRANDING_DIR;
+  });
+
+  it('stores a pond logo, reports it, and serves it under the pond scope', async () => {
+    const view = await api()
+      .post(`/api/v1/ponds/${pondId}/branding/logo?variant=light`)
+      .set('Cookie', ownerCookie)
+      .attach('file', png(64), 'logo.png')
+      .expect(201);
+    expect(view.body.logo).toMatchObject({ width: 64, height: 64 });
+
+    const served = await api()
+      .get(`/api/v1/branding/logo?variant=light&pond=${pondId}`)
+      .expect(200);
+    expect(served.headers['content-type']).toContain('image/png');
+
+    // Without the pond scope the instance level answers — 404 here, since no
+    // instance logo is set. The two levels never leak into each other.
+    await api().get('/api/v1/branding/logo?variant=light').expect(404);
+  });
+
+  it('charges the pond quota and gives the bytes back when the logo is replaced', async () => {
+    const usageOf = async (): Promise<number> =>
+      Number(
+        (
+          await prisma.pondUsage.findUnique({
+            where: { pondId },
+            select: { storageBytesUsed: true },
+          })
+        )?.storageBytesUsed ?? 0,
+      );
+    const before = await usageOf();
+
+    const big = png(120);
+    await api()
+      .post(`/api/v1/ponds/${pondId}/branding/logo?variant=dark`)
+      .set('Cookie', ownerCookie)
+      .attach('file', big, 'logo.png')
+      .expect(201);
+    const afterUpload = await usageOf();
+    expect(afterUpload).toBe(before + big.length);
+
+    // Replacing releases the old reservation first — otherwise re-uploading
+    // the same logo would eat the quota again and again.
+    await api()
+      .post(`/api/v1/ponds/${pondId}/branding/logo?variant=dark`)
+      .set('Cookie', ownerCookie)
+      .attach('file', big, 'logo.png')
+      .expect(201);
+    expect(await usageOf()).toBe(afterUpload);
+
+    await api()
+      .delete(`/api/v1/ponds/${pondId}/branding/logo?variant=dark`)
+      .set('Cookie', ownerCookie)
+      .expect(200);
+    expect(await usageOf()).toBe(before);
+  });
+
+  it('refuses SVG at the pond level too — the rules do not relax for a pond admin', async () => {
+    const res = await api()
+      .post(`/api/v1/ponds/${pondId}/branding/logo?variant=light`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('<svg xmlns="x"><script/></svg>'), 'x.png')
+      .expect(400);
+    expect(res.body.code).toBe('branding_svg_rejected');
+  });
+
+  it('lets a member read the pond branding but not change it', async () => {
+    await api().get(`/api/v1/ponds/${pondId}/branding`).set('Cookie', memberCookie).expect(200);
+    await api()
+      .post(`/api/v1/ponds/${pondId}/branding/logo?variant=light`)
+      .set('Cookie', memberCookie)
+      .attach('file', png(32), 'x.png')
+      .expect(403);
+    await api()
+      .delete(`/api/v1/ponds/${pondId}/branding/favicon`)
+      .set('Cookie', memberCookie)
+      .expect(403);
+  });
+
+  it('purging the pond removes its branding files', async () => {
+    // A pond of its own, so the purge does not take the shared fixture with it.
+    const ownerRow = await prisma.user.findFirstOrThrow({ where: { username: owner.username } });
+    const created = await prisma.pond.create({
+      data: {
+        name: `Purge Branding ${suffix}`,
+        slug: `purge-branding-${suffix}`,
+        type: 'SHARED',
+        ownerId: ownerRow.id,
+      },
+    });
+    // Raw grant row, before this pond's first permission query — the
+    // documented exception to "grants through the API".
+    await grantOwnerAdmin(prisma, created.id, ownerRow.id);
+    await api()
+      .post(`/api/v1/ponds/${created.id}/branding/logo?variant=light`)
+      .set('Cookie', ownerCookie)
+      .attach('file', png(48), 'logo.png')
+      .expect(201);
+    expect(await storage.read(BrandingService.pondLogoKey(created.id, 'light'))).not.toBeNull();
+
+    await prisma.pond.update({ where: { id: created.id }, data: { deletedAt: new Date() } });
+    const trash = app.get(TrashService);
+    await trash.purgePondNow(ownerRow, created.id);
+
+    // The purge standard is absolute: after it nothing referencing the pond
+    // survives — rows OR files.
+    expect(await storage.read(BrandingService.pondLogoKey(created.id, 'light'))).toBeNull();
+  });
+});

apps/api/src/common/mask-token-param.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest';
+
+import { maskTokenParam } from './mask-token-param';
+
+describe('maskTokenParam (issue #191)', () => {
+  it('masks a token as the only query parameter', () => {
+    expect(maskTokenParam('/api/v1/public/p/feed.xml?token=dt_feed_abc123')).toBe(
+      '/api/v1/public/p/feed.xml?token=[redacted]',
+    );
+  });
+
+  it('masks a token between other parameters and stops at delimiters', () => {
+    expect(maskTokenParam('/x?a=1&token=secret&b=2')).toBe('/x?a=1&token=[redacted]&b=2');
+    expect(maskTokenParam('/x?token=secret#frag')).toBe('/x?token=[redacted]#frag');
+  });
+
+  it('leaves URLs without a token parameter untouched', () => {
+    expect(maskTokenParam('/api/v1/ponds?filter=token')).toBe('/api/v1/ponds?filter=token');
+    expect(maskTokenParam('/api/v1/readyz')).toBe('/api/v1/readyz');
+  });
+
+  it('passes undefined through', () => {
+    expect(maskTokenParam(undefined)).toBeUndefined();
+  });
+});

apps/api/src/common/mask-token-param.ts

@@ -0,0 +1,9 @@
+/**
+ * Masks credential-bearing `token` query parameters before a URL reaches
+ * the request log (issue #191): feed tokens travel in the query string
+ * because feed readers cannot send headers, and the api's own log must
+ * not become the place where that long-lived credential is stored.
+ */
+export function maskTokenParam<T extends string | undefined>(url: T): T {
+  return url?.replace(/([?&]token=)[^&#]*/gi, '$1[redacted]') as T;
+}

apps/api/src/common/security-headers.e2e.test.ts

@@ -0,0 +1,74 @@
+import { INestApplication } from '@nestjs/common';
+import { Test } from '@nestjs/testing';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { AppModule } from '../app.module';
+
+// Boots the AppModule without a database (like health.e2e.test.ts): the
+// middleware under test runs before any route logic, so the always-on
+// healthz endpoint is a representative response (issue #197).
+describe('security response headers & CORS (e2e, issue #197)', () => {
+  let app: INestApplication;
+  const appOrigin = 'http://localhost:5173'; // APP_BASE_URL default origin
+
+  beforeAll(async () => {
+    process.env.NODE_ENV = 'test';
+    process.env.DATABASE_URL ??= 'postgresql://nobody:nothing@127.0.0.1:59999/absent';
+    const moduleRef = await Test.createTestingModule({ imports: [AppModule] }).compile();
+    app = moduleRef.createNestApplication();
+    app.setGlobalPrefix('api/v1');
+    await app.init();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  it('stamps the full header set on a representative response', async () => {
+    const res = await request(app.getHttpServer()).get('/api/v1/healthz').expect(200);
+    expect(res.headers['strict-transport-security']).toBe('max-age=31536000');
+    expect(res.headers['x-content-type-options']).toBe('nosniff');
+    expect(res.headers['referrer-policy']).toBe('no-referrer');
+    // SAMEORIGIN, not DENY — the plugin sandbox frame is embedded
+    // same-origin (plugins.e2e.db.test.ts asserts the frame side).
+    expect(res.headers['x-frame-options']).toBe('SAMEORIGIN');
+    expect(res.headers['permissions-policy']).toBe(
+      'camera=(), microphone=(), geolocation=(), payment=(), usb=()',
+    );
+  });
+
+  it('stamps the headers on error responses too (unknown route)', async () => {
+    const res = await request(app.getHttpServer()).get('/api/v1/does-not-exist').expect(404);
+    expect(res.headers['x-content-type-options']).toBe('nosniff');
+    expect(res.headers['x-frame-options']).toBe('SAMEORIGIN');
+  });
+
+  it('grants a foreign origin nothing (no ACAO), while varying on Origin', async () => {
+    const res = await request(app.getHttpServer())
+      .get('/api/v1/healthz')
+      .set('Origin', 'https://attacker.example')
+      .expect(200);
+    expect(res.headers['access-control-allow-origin']).toBeUndefined();
+    expect(res.headers['access-control-allow-credentials']).toBeUndefined();
+    expect(res.headers.vary).toContain('Origin');
+  });
+
+  it("echoes only the app's own origin, with the credentials rule stated", async () => {
+    const res = await request(app.getHttpServer())
+      .get('/api/v1/healthz')
+      .set('Origin', appOrigin)
+      .expect(200);
+    expect(res.headers['access-control-allow-origin']).toBe(appOrigin);
+    expect(res.headers['access-control-allow-credentials']).toBe('true');
+  });
+
+  it('leaves a foreign preflight ungranted (no CORS response headers)', async () => {
+    const res = await request(app.getHttpServer())
+      .options('/api/v1/healthz')
+      .set('Origin', 'https://attacker.example')
+      .set('Access-Control-Request-Method', 'POST');
+    expect(res.headers['access-control-allow-origin']).toBeUndefined();
+    expect(res.headers['access-control-allow-methods']).toBeUndefined();
+  });
+});

apps/api/src/common/security-headers.middleware.ts

@@ -0,0 +1,54 @@
+import { Injectable, NestMiddleware } from '@nestjs/common';
+import type { NextFunction, Request, Response } from 'express';
+
+import { AppConfig } from '../config/app-config.service';
+
+/**
+ * Security response headers and the CORS stance for every api response
+ * (issue #197). Hand-rolled instead of `helmet`: the header set is small
+ * enough to own, every value below is a deliberate decision, and the api
+ * gains no transitive dependency. Wired via the AppModule's
+ * MiddlewareConsumer so the test harness (createTestApp) exercises the
+ * exact production middleware — rationale per header in
+ * docs/architecture/security.md §Security response headers & CORS.
+ */
+@Injectable()
+export class SecurityHeadersMiddleware implements NestMiddleware {
+  /** The one origin the SPA is served from; the only origin CORS ever echoes. */
+  private readonly allowedOrigin: string;
+
+  constructor(config: AppConfig) {
+    this.allowedOrigin = new URL(config.env.APP_BASE_URL).origin;
+  }
+
+  use(req: Request, res: Response, next: NextFunction): void {
+    // No includeSubDomains: the api cannot speak for sibling subdomains it
+    // does not control (e.g. a support desk on the same apex). Browsers
+    // ignore HSTS over plain http, so sending it unconditionally is safe.
+    res.setHeader('Strict-Transport-Security', 'max-age=31536000');
+    res.setHeader('X-Content-Type-Options', 'nosniff');
+    // Page paths are permission-scoped knowledge — leak them to no one.
+    res.setHeader('Referrer-Policy', 'no-referrer');
+    // SAMEORIGIN, deliberately not DENY: the plugin sandbox (ADR 0008)
+    // embeds /api/v1/plugins/<id>/<version>/frame same-origin, and the
+    // frame's own CSP carries no frame-ancestors — this header governs.
+    res.setHeader('X-Frame-Options', 'SAMEORIGIN');
+    // Deny the powerful features outright; nothing in the app uses them.
+    res.setHeader(
+      'Permissions-Policy',
+      'camera=(), microphone=(), geolocation=(), payment=(), usb=()',
+    );
+
+    // CORS: no foreign origin is granted anything — only the app's own
+    // origin is ever echoed (where browsers do not consult CORS anyway, as
+    // same-origin; the echo states the decision rather than enabling a
+    // caller). Same-origin requests never preflight, so no OPTIONS
+    // handling is needed. Vary on every response keeps caches honest.
+    res.vary('Origin');
+    if (req.headers.origin === this.allowedOrigin) {
+      res.setHeader('Access-Control-Allow-Origin', this.allowedOrigin);
+      res.setHeader('Access-Control-Allow-Credentials', 'true');
+    }
+    next();
+  }
+}

apps/api/src/favorites/favorites.controller.ts

@@ -0,0 +1,39 @@
+import { Controller, Delete, Get, Param, Put, Req } from '@nestjs/common';
+import type { FavoriteStateView, PageFavoritesView } from '@dorfteich/shared';
+
+import { AuthedRequest } from '../auth/auth.guard';
+import { AuthenticatedOnly } from '../permissions/permission.decorators';
+import { FavoritesService } from './favorites.service';
+
+/** Star/unstar pages + the per-pond favorites of the account (issue #132). */
+@Controller()
+export class FavoritesController {
+  constructor(private readonly favorites: FavoritesService) {}
+
+  @Get('ponds/:pondId/favorites')
+  @AuthenticatedOnly()
+  async list(
+    @Param('pondId') pondId: string,
+    @Req() request: AuthedRequest,
+  ): Promise<PageFavoritesView> {
+    return this.favorites.listForPond(request.user!, pondId);
+  }
+
+  @Put('pages/:id/favorite')
+  @AuthenticatedOnly()
+  async favorite(
+    @Param('id') id: string,
+    @Req() request: AuthedRequest,
+  ): Promise<FavoriteStateView> {
+    return this.favorites.favorite(request.user!, id);
+  }
+
+  @Delete('pages/:id/favorite')
+  @AuthenticatedOnly()
+  async unfavorite(
+    @Param('id') id: string,
+    @Req() request: AuthedRequest,
+  ): Promise<FavoriteStateView> {
+    return this.favorites.unfavorite(request.user!, id);
+  }
+}

apps/api/src/favorites/favorites.e2e.db.test.ts

@@ -0,0 +1,177 @@
+import { INestApplication } from '@nestjs/common';
+import type { FavoriteStateView, PageFavoritesView } from '@dorfteich/shared';
+import { PrismaClient, User } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, sessionCookieOf } from '../testing/test-app';
+import { createTestPrisma, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+/**
+ * Personal favorites end to end (issue #132): per-user round-trip and
+ * isolation, read-gated starring (#60 semantics), idempotency, and the
+ * trash/restore/purge lifecycle (a star survives the trash, purge cascades
+ * it away).
+ */
+describe.skipIf(!hasTestDb)('favorites (e2e, issue #132)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  const suffix = uniqueSuffix();
+  const password = 'sterne fuer seiten 1';
+  const users: Record<string, User> = {};
+  const cookies: Record<string, string> = {};
+  let pondId: string;
+
+  const api = () => request(app.getHttpServer());
+
+  async function makeUser(handle: string): Promise<void> {
+    const service = app.get(UsersService);
+    const username = `fav-${handle}-${suffix}`;
+    const user = await service.createUser({
+      username,
+      email: `${username}@example.org`,
+      displayName: `Fav ${handle}`,
+      password,
+      locale: 'en',
+    });
+    await service.markEmailVerified(user.id);
+    users[handle] = user;
+    cookies[handle] = sessionCookieOf(
+      await api()
+        .post('/api/v1/auth/login')
+        .send({ usernameOrEmail: username, password })
+        .expect(200),
+    );
+  }
+
+  async function createPage(cookie: string, title: string): Promise<string> {
+    const res = await api()
+      .post(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', cookie)
+      .send({ title })
+      .expect(201);
+    return (res.body as { id: string }).id;
+  }
+
+  async function favoritesOf(cookie: string): Promise<string[]> {
+    const res = await api()
+      .get(`/api/v1/ponds/${pondId}/favorites`)
+      .set('Cookie', cookie)
+      .expect(200);
+    return (res.body as PageFavoritesView).pageIds;
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    await prisma.rateLimit.deleteMany({});
+    app = await createTestApp();
+    for (const handle of ['owner', 'member', 'outsider']) await makeUser(handle);
+
+    const pond = await prisma.pond.create({
+      data: {
+        slug: `fav-pond-${suffix}`,
+        name: 'Favorite Pond',
+        type: 'SHARED',
+        ownerId: users.owner!.id,
+      },
+    });
+    pondId = pond.id;
+    for (const [handle, role] of [
+      ['owner', 'POND_ADMIN'],
+      ['member', 'EDITOR'],
+    ] as const) {
+      await prisma.roleGrant.create({
+        data: {
+          pondId,
+          subjectType: 'USER',
+          subjectId: users[handle]!.id,
+          role,
+          scopeType: 'POND',
+          effect: 'ALLOW',
+          createdBy: users.owner!.id,
+        },
+      });
+    }
+  });
+
+  afterAll(async () => {
+    const ids = Object.values(users).map((u) => u.id);
+    await prisma.pageFavorite.deleteMany({ where: { userId: { in: ids } } });
+    await prisma.roleGrant.deleteMany({ where: { pondId } });
+    await prisma.page.deleteMany({ where: { pondId } });
+    await prisma.pond.deleteMany({ where: { id: pondId } });
+    await prisma.auditEntry.deleteMany({ where: { actorId: { in: ids } } });
+    await prisma.session.deleteMany({ where: { userId: { in: ids } } });
+    await prisma.userIdentity.deleteMany({ where: { userId: { in: ids } } });
+    await prisma.user.deleteMany({ where: { id: { in: ids } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('round-trips the star per user and stays idempotent', async () => {
+    const pageId = await createPage(cookies.owner!, 'Starred page');
+
+    const on = (
+      await api().put(`/api/v1/pages/${pageId}/favorite`).set('Cookie', cookies.member!).expect(200)
+    ).body as FavoriteStateView;
+    expect(on.favorite).toBe(true);
+    // Starring twice is fine — still exactly one favorite.
+    await api().put(`/api/v1/pages/${pageId}/favorite`).set('Cookie', cookies.member!).expect(200);
+
+    expect(await favoritesOf(cookies.member!)).toEqual([pageId]);
+    // Personal, not pond-wide: the owner's list stays empty.
+    expect(await favoritesOf(cookies.owner!)).toEqual([]);
+
+    const off = (
+      await api()
+        .delete(`/api/v1/pages/${pageId}/favorite`)
+        .set('Cookie', cookies.member!)
+        .expect(200)
+    ).body as FavoriteStateView;
+    expect(off.favorite).toBe(false);
+    expect(await favoritesOf(cookies.member!)).toEqual([]);
+    // Unstarring an unstarred page is a no-op, not an error.
+    await api()
+      .delete(`/api/v1/pages/${pageId}/favorite`)
+      .set('Cookie', cookies.member!)
+      .expect(200);
+  });
+
+  it('gates starring and the pond list behind read access (404, #60)', async () => {
+    const pageId = await createPage(cookies.owner!, 'Hidden page');
+    await api()
+      .put(`/api/v1/pages/${pageId}/favorite`)
+      .set('Cookie', cookies.outsider!)
+      .expect(404);
+    await api()
+      .get(`/api/v1/ponds/${pondId}/favorites`)
+      .set('Cookie', cookies.outsider!)
+      .expect(404);
+  });
+
+  it('hides trashed favorites, revives them on restore, cascades on purge', async () => {
+    const pageId = await createPage(cookies.owner!, 'Cycling page');
+    await api().put(`/api/v1/pages/${pageId}/favorite`).set('Cookie', cookies.member!).expect(200);
+
+    // Trash: the page drops out of the favorites list, the row stays.
+    await prisma.page.update({
+      where: { id: pageId },
+      data: { deletedAt: new Date(), deletedBy: users.owner!.id },
+    });
+    expect(await favoritesOf(cookies.member!)).toEqual([]);
+    expect(await prisma.pageFavorite.count({ where: { pageId } })).toBe(1);
+
+    // Restore: the star is back without re-starring.
+    await prisma.page.update({ where: { id: pageId }, data: { deletedAt: null, deletedBy: null } });
+    expect(await favoritesOf(cookies.member!)).toEqual([pageId]);
+
+    // Purge: the FK cascade removes the favorite rows for good.
+    await prisma.page.update({
+      where: { id: pageId },
+      data: { deletedAt: new Date(), deletedBy: users.owner!.id },
+    });
+    await api().delete(`/api/v1/pages/${pageId}/purge`).set('Cookie', cookies.owner!).expect(204);
+    expect(await prisma.pageFavorite.count({ where: { pageId } })).toBe(0);
+  });
+});

apps/api/src/favorites/favorites.module.ts

@@ -0,0 +1,13 @@
+import { Module } from '@nestjs/common';
+
+import { PermissionsModule } from '../permissions/permissions.module';
+
+import { FavoritesController } from './favorites.controller';
+import { FavoritesService } from './favorites.service';
+
+@Module({
+  imports: [PermissionsModule],
+  controllers: [FavoritesController],
+  providers: [FavoritesService],
+})
+export class FavoritesModule {}

apps/api/src/favorites/favorites.service.ts

@@ -0,0 +1,57 @@
+import { Injectable, NotFoundException } from '@nestjs/common';
+import type { FavoriteStateView, PageFavoritesView } from '@dorfteich/shared';
+import { User } from '@prisma/client';
+
+import { PermissionService } from '../permissions/permission.service';
+import { PrismaService } from '../prisma/prisma.service';
+
+/**
+ * Personal page favorites (issue #132): a per-user star, deliberately NOT
+ * pond-wide (see the planning pivot on the issue). Starring needs read
+ * access to a live page (404 hides what the user cannot see, #60) — it is
+ * a note-to-self, not a page modification, so write access is NOT required.
+ * Both directions are idempotent, mirroring the watches service.
+ */
+@Injectable()
+export class FavoritesService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly permissions: PermissionService,
+  ) {}
+
+  async favorite(user: User, pageId: string): Promise<FavoriteStateView> {
+    const page = await this.prisma.page.findFirst({
+      where: { id: pageId, deletedAt: null },
+      select: { id: true, pondId: true },
+    });
+    if (!page || !(await this.permissions.canAccessPage(user, page, 'read'))) {
+      throw new NotFoundException();
+    }
+    await this.prisma.pageFavorite.upsert({
+      where: { userId_pageId: { userId: user.id, pageId } },
+      create: { userId: user.id, pageId },
+      update: {},
+    });
+    return { favorite: true };
+  }
+
+  async unfavorite(user: User, pageId: string): Promise<FavoriteStateView> {
+    await this.prisma.pageFavorite.deleteMany({ where: { userId: user.id, pageId } });
+    return { favorite: false };
+  }
+
+  /** The user's own favorites within one pond, sliced to pages they can
+   * still read — a revoked page must not confirm its continued existence. */
+  async listForPond(user: User, pondId: string): Promise<PageFavoritesView> {
+    if (!(await this.permissions.canSeePond(user, pondId))) throw new NotFoundException();
+    const rows = await this.prisma.pageFavorite.findMany({
+      where: { userId: user.id, page: { pondId, deletedAt: null } },
+      select: { pageId: true, page: { select: { id: true, pondId: true } } },
+    });
+    const pageIds: string[] = [];
+    for (const row of rows) {
+      if (await this.permissions.canAccessPage(user, row.page, 'read')) pageIds.push(row.pageId);
+    }
+    return { pageIds };
+  }
+}

apps/api/src/files/attachment-integrity.e2e.db.test.ts

@@ -0,0 +1,152 @@
+import { createHash } from 'node:crypto';
+
+import { INestApplication, InternalServerErrorException } from '@nestjs/common';
+import { PrismaClient, User } from '@prisma/client';
+import request from 'supertest';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { AuthTokensService } from '../auth/auth-tokens.service';
+import { createTestApp } from '../testing/test-app';
+import { createTestPrisma, deletePondsWhere, hasTestDb, uniqueSuffix } from '../testing/test-db';
+import { UsersService } from '../users/users.service';
+
+import { FileStorageService } from './file-storage.service';
+import { FilesService } from './files.service';
+
+const PNG_SIGNATURE = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]);
+const pngBuffer = (payload: string): Buffer => Buffer.concat([PNG_SIGNATURE, Buffer.from(payload)]);
+const sha256 = (buffer: Buffer): string => createHash('sha256').update(buffer).digest('hex');
+
+/**
+ * Attachment integrity (issue #199): uploads store the SHA-256 of the
+ * written bytes, downloads verify it and fail closed (audited) on mismatch,
+ * and the nightly backfill hashes pre-#199 rows idempotently, reporting
+ * unreadable files instead of skipping them.
+ */
+describe.skipIf(!hasTestDb)('attachment integrity (e2e, issue #199)', () => {
+  let app: INestApplication;
+  let prisma: PrismaClient;
+  let files: FilesService;
+  let storage: FileStorageService;
+  let user: User;
+  let pondId: string;
+  const suffix = uniqueSuffix();
+
+  async function uploadPng(payload: string): Promise<{ id: string; bytes: Buffer }> {
+    const bytes = pngBuffer(payload);
+    const view = await files.upload(user, pondId, {
+      buffer: bytes,
+      size: bytes.length,
+      originalname: `${payload}.png`,
+    });
+    return { id: view.id, bytes };
+  }
+
+  beforeAll(async () => {
+    prisma = createTestPrisma();
+    app = await createTestApp();
+    files = app.get(FilesService);
+    storage = app.get(FileStorageService);
+
+    const users = app.get(UsersService);
+    user = await users.createUser({
+      username: `ines-integrity-${suffix}`,
+      email: `ines-integrity-${suffix}@example.org`,
+      displayName: `Ines Integrity ${suffix}`,
+      password: 'jedes byte bleibt wie es war 1',
+      locale: 'en',
+    });
+    // Verification via the endpoint (not markEmailVerified) because only the
+    // endpoint creates the personal pond the uploads go into.
+    const token = await app.get(AuthTokensService).issue(user.id, 'EMAIL_VERIFICATION', 600);
+    await request(app.getHttpServer())
+      .post('/api/v1/auth/verify-email')
+      .send({ token })
+      .expect(204);
+    const pond = await prisma.pond.findFirstOrThrow({ where: { ownerId: user.id } });
+    pondId = pond.id;
+  });
+
+  afterAll(async () => {
+    await prisma.auditEntry.deleteMany({
+      where: { action: 'file.integrity_failed', details: { path: ['pondId'], equals: pondId } },
+    });
+    await prisma.attachment.deleteMany({ where: { pondId } });
+    const where = { pond: { owner: { username: { contains: suffix } } } };
+    await prisma.roleGrant.deleteMany({ where });
+    await deletePondsWhere(prisma, { owner: { username: { contains: suffix } } });
+    await prisma.user.deleteMany({ where: { username: { contains: suffix } } });
+    await prisma.$disconnect();
+    await app.close();
+  });
+
+  it('stores the hash of the written bytes at upload', async () => {
+    const { id, bytes } = await uploadPng('honest-upload');
+    const row = await prisma.attachment.findUniqueOrThrow({ where: { id } });
+    expect(row.sha256).toBe(sha256(bytes));
+  });
+
+  it('serves an intact file and fails closed, audited, on a tampered one', async () => {
+    const { id, bytes } = await uploadPng('will-be-tampered');
+
+    // Intact: the download succeeds and streams the exact bytes.
+    const intact = await files.download(null, id, { actorId: null, sessionKey: 'anon' });
+    const chunks: Buffer[] = [];
+    for await (const chunk of intact.stream) chunks.push(chunk as Buffer);
+    expect(Buffer.concat(chunks).equals(bytes)).toBe(true);
+
+    // Tampered on disk (row untouched): fail closed with the dedicated code.
+    await storage.save(pondId, id, pngBuffer('evil-replacement'));
+    const failure = await files
+      .download(null, id, { actorId: null, sessionKey: 'anon' })
+      .catch((error: unknown) => error);
+    expect(failure).toBeInstanceOf(InternalServerErrorException);
+    expect((failure as InternalServerErrorException).getResponse()).toMatchObject({
+      code: 'attachment_integrity_failure',
+    });
+
+    // The mismatch is on the audit trail with both hashes.
+    const audit = await prisma.auditEntry.findFirst({
+      where: { action: 'file.integrity_failed', targetId: id },
+    });
+    expect(audit).not.toBeNull();
+    expect(audit!.details).toMatchObject({
+      expected: sha256(bytes),
+      actual: sha256(pngBuffer('evil-replacement')),
+    });
+  });
+
+  it('backfills missing hashes idempotently and reports unreadable files', async () => {
+    const readable = await uploadPng('backfill-me');
+    const unreadable = await uploadPng('bytes-will-vanish');
+    await prisma.attachment.updateMany({
+      where: { id: { in: [readable.id, unreadable.id] } },
+      data: { sha256: null },
+    });
+    await storage.delete(pondId, unreadable.id);
+
+    // A null-hash row is served unverified (pre-#199 status quo).
+    const unverified = await files.download(null, readable.id, {
+      actorId: null,
+      sessionKey: 'anon',
+    });
+    expect(unverified.attachment.sha256).toBeNull();
+
+    const first = await files.backfillHashes();
+    expect(first.hashed).toBeGreaterThanOrEqual(1);
+    expect(first.unreadable).toBeGreaterThanOrEqual(1);
+    const rehashed = await prisma.attachment.findUniqueOrThrow({ where: { id: readable.id } });
+    expect(rehashed.sha256).toBe(sha256(readable.bytes));
+
+    // The unreadable row keeps its null hash — reported, retried next run,
+    // never silently marked done.
+    const vanished = await prisma.attachment.findUniqueOrThrow({ where: { id: unreadable.id } });
+    expect(vanished.sha256).toBeNull();
+
+    // Idempotent: a second run finds nothing new to hash here.
+    const second = await files.backfillHashes();
+    const third = await prisma.attachment.findUniqueOrThrow({ where: { id: readable.id } });
+    expect(third.sha256).toBe(sha256(readable.bytes));
+    expect(second.unreadable).toBeGreaterThanOrEqual(1);
+  });
+});

apps/api/src/files/file-storage.service.ts

@@ -1,5 +1,5 @@
 import { createReadStream } from 'node:fs';
-import { access, mkdir, rm, writeFile } from 'node:fs/promises';
+import { access, mkdir, readdir, readFile, rm, stat, writeFile } from 'node:fs/promises';
 import { join } from 'node:path';
 import type { Readable } from 'node:stream';
 
@@ -30,6 +30,13 @@ export class FileStorageService {
     return createReadStream(this.pathFor(pondId, fileId));
   }
 
+  /** The complete stored bytes. Used where the caller must see the whole
+   * object before serving a single byte of it — integrity verification
+   * (issue #199) cannot work on a stream that is already leaving. */
+  read(pondId: string, fileId: string): Promise<Buffer> {
+    return readFile(this.pathFor(pondId, fileId));
+  }
+
   /** Whether the file's bytes are actually on disk. Used by the pond export to
    * skip an attachment whose bytes are missing (data drift) rather than crash
    * the archive stream (issue #65). */
@@ -46,4 +53,37 @@ export class FileStorageService {
   async delete(pondId: string, fileId: string): Promise<void> {
     await rm(this.pathFor(pondId, fileId), { force: true });
   }
+
+  /**
+   * Every stored file with its modification time, for the orphan sweep's
+   * volume↔database direction (issue #194, ADR 0011). A missing uploads
+   * directory is an empty volume, not an error.
+   */
+  async listStored(): Promise<{ pondId: string; fileId: string; mtimeMs: number }[]> {
+    const root = this.config.env.UPLOADS_DIR;
+    const result: { pondId: string; fileId: string; mtimeMs: number }[] = [];
+    let pondDirs: string[];
+    try {
+      pondDirs = await readdir(root);
+    } catch {
+      return result;
+    }
+    for (const pondId of pondDirs) {
+      let files: string[];
+      try {
+        files = await readdir(join(root, pondId));
+      } catch {
+        continue; // not a directory or vanished mid-walk
+      }
+      for (const fileId of files) {
+        try {
+          const info = await stat(join(root, pondId, fileId));
+          if (info.isFile()) result.push({ pondId, fileId, mtimeMs: info.mtimeMs });
+        } catch {
+          // vanished mid-walk — the next sweep sees the truth
+        }
+      }
+    }
+    return result;
+  }
 }

apps/api/src/files/files.controller.ts

@@ -27,6 +27,7 @@ import {
   RequiresPagePermission,
   RequiresPondRole,
 } from '../permissions/permission.decorators';
+import { readActorOf } from '../read-trail/read-actor';
 
 import { FilesService } from './files.service';
 
@@ -90,14 +91,18 @@ export class FilesController {
     @Req() request: AuthedRequest,
     @Res({ passthrough: true }) response: Response,
   ): Promise<StreamableFile> {
-    const { attachment, stream, inline } = await this.files.download(request.user ?? null, fileId);
+    const { attachment, stream, inline, downloadName } = await this.files.download(
+      request.user ?? null,
+      fileId,
+      readActorOf(request),
+    );
     response.set('X-Content-Type-Options', 'nosniff');
     // Attachments are immutable — a new upload always gets a new id.
     response.set('Cache-Control', 'private, max-age=31536000, immutable');
     const kind = inline ? 'inline' : 'attachment';
     return new StreamableFile(stream, {
       type: attachment.mimeType,
-      disposition: `${kind}; filename="${encodeURIComponent(attachment.fileName)}"`,
+      disposition: `${kind}; filename="${encodeURIComponent(downloadName)}"`,
     });
   }
 

apps/api/src/files/files.e2e.db.test.ts

@@ -301,7 +301,6 @@ describe.skipIf(!hasTestDb)('files (e2e, issue #27)', () => {
     await api().get(`/api/v1/media/${uploaded.body.id}`).set('Cookie', ownerCookie).expect(200);
     const stillThere = await prisma.attachment.findUnique({ where: { id: uploaded.body.id } });
     expect(stillThere).not.toBeNull();
-    expect(stillThere?.deletedAt).toBeNull();
   });
 
   it('lists a page attachment for the page and links it (#61)', async () => {
@@ -328,6 +327,121 @@ describe.skipIf(!hasTestDb)('files (e2e, issue #27)', () => {
     expect(item.pageTitle).toBe(`Page Files ${suffix}`);
   });
 
+  it('prefixes downloads of classified attachments; unset pageId fails closed (issue #212)', async () => {
+    const page = await api()
+      .post(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', ownerCookie)
+      .send({ title: `Classified Files ${suffix}` })
+      .expect(201);
+
+    const uploaded = await api()
+      .post(`/api/v1/pages/${page.body.id}/files`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('%PDF-1.4 classified content'), 'geheim.pdf')
+      .expect(201);
+
+    // Unclassified page: unchanged filename.
+    const openServed = await api()
+      .get(`/api/v1/media/${uploaded.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(openServed.headers['content-disposition']).toContain('filename="geheim.pdf"');
+
+    // Classified page: the documented VS-NfD_ prefix.
+    await prisma.page.update({
+      where: { id: page.body.id as string },
+      data: { classification: 'VS_NFD' },
+    });
+    const served = await api()
+      .get(`/api/v1/media/${uploaded.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(served.headers['content-disposition']).toContain('filename="VS-NfD_geheim.pdf"');
+
+    // pageId unset (paste-then-insert): fails closed to the pond's highest
+    // level — the pond now contains a classified page, so the orphan upload
+    // is served with the prefix too.
+    const orphan = await api()
+      .post(`/api/v1/ponds/${pondId}/files`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('%PDF-1.4 orphan bytes'), 'lose-datei.pdf')
+      .expect(201);
+    const orphanServed = await api()
+      .get(`/api/v1/media/${orphan.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(orphanServed.headers['content-disposition']).toContain(
+      'filename="VS-NfD_lose-datei.pdf"',
+    );
+
+    // Back to all-open: the orphan serves unprefixed again.
+    await prisma.page.update({
+      where: { id: page.body.id as string },
+      data: { classification: 'UNCLASSIFIED' },
+    });
+    const openOrphan = await api()
+      .get(`/api/v1/media/${orphan.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(openOrphan.headers['content-disposition']).toContain('filename="lose-datei.pdf"');
+  });
+
+  it('blocks uploads to classified pages server-side when the policy says so (issue #213)', async () => {
+    const settings = app.get(InstanceSettingsService);
+    const page = await api()
+      .post(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', ownerCookie)
+      .send({ title: `Blocked Uploads ${suffix}` })
+      .expect(201);
+    await prisma.page.update({
+      where: { id: page.body.id as string },
+      data: { classification: 'VS_NFD' },
+    });
+
+    // Default policy `warn`: the upload is allowed (the UI shows the notice).
+    await api()
+      .post(`/api/v1/pages/${page.body.id}/files`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('%PDF-1.4 warned upload'), 'warned.pdf')
+      .expect(201);
+
+    await settings.set('classification.uploadPolicy', 'block', 'test');
+    try {
+      // Enforced server-side, not only in the UI.
+      const blocked = await api()
+        .post(`/api/v1/pages/${page.body.id}/files`)
+        .set('Cookie', ownerCookie)
+        .attach('file', Buffer.from('%PDF-1.4 blocked upload'), 'blocked.pdf')
+        .expect(403);
+      expect((blocked.body as { code: string }).code).toBe('classified_upload_blocked');
+
+      // Unclassified pages stay uploadable under `block`.
+      const open = await api()
+        .post(`/api/v1/ponds/${pondId}/pages`)
+        .set('Cookie', ownerCookie)
+        .send({ title: `Open Uploads ${suffix}` })
+        .expect(201);
+      await api()
+        .post(`/api/v1/pages/${open.body.id}/files`)
+        .set('Cookie', ownerCookie)
+        .attach('file', Buffer.from('%PDF-1.4 open upload'), 'open.pdf')
+        .expect(201);
+    } finally {
+      await settings.set('classification.uploadPolicy', 'warn', 'test');
+      await prisma.instanceSetting.deleteMany({
+        where: { key: 'classification.uploadPolicy' },
+      });
+    }
+  });
+
   it('pond file manager reports usage, orphans, and page links (#61)', async () => {
     const page = await api()
       .post(`/api/v1/ponds/${pondId}/pages`)