A classified page's .md carries the level in YAML frontmatter AND the
marking line at top and bottom; unclassified files are byte-identical to
before. Every pond archive (incl. the per-pond folders of the account
data export) ships a manifest.json listing each file with its level and
stating the highest level once at archive level — media inherits the
highest classification among the readable pages referencing it
(fail-closed). Round trip: the importer recognizes exactly our
frontmatter block, strips it plus the imprint lines, and creates the
page at least at the imported level (content must not escape its marking
by traveling through a ZIP) — pinned by unit and e2e round-trip tests.
Foreign frontmatter passes through unchanged; the Obsidian vault import
keeps its own frontmatter modes.
Co-Authored-By: Claude Fable 5 (1M context) <noreply@anthropic.com>
