Prisma models per data-model.md: users (status enum, site-admin flag),
user_identities (password provider now, OIDC later — subject is the
stable user id), sessions (hashed ids), auth_tokens (hashed, single-
use), plus rate_limits and mail_outbox for the upcoming M1 stories.
UsersService creates accounts transactionally with Argon2id-hashed
password identities (OWASP parameters, rehash detection) and maps
uniqueness violations to field-level conflicts. Database-backed suites
run when TEST_DATABASE_URL is set — locally against the dev db, in CI
via a new postgres service container; shared auth schemas (username,
password policy incl. common-password blocklist) ship with tests.
Closes#10
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
