PostfixAdmin-RS 0.1.0 – validation of this release

Compiler gate (rustc 1.97 offline with vendored crates, edition 2024):
- cargo build: PASS
- cargo clippy --all-targets -- -D warnings: PASS
- cargo test: PASS (unit tests incl. quota/limit rules, CIDR/proxy resolution,
  recipient delimiter, vacation dates, fetchmail base64, password vectors)
- scripts/validate-release-static.py: PASS
- scripts/i18n/build.py: PASS (no missing Polish strings)

Database:
- PostgreSQL 16: --init-schema on an empty database, second run idempotent,
  --create-superadmin, --check-config, --integrity-check: PASS
- SQLite (development mock built by the same schema code): PASS
- MySQL/MariaDB: not available in the build environment; queries use the same
  portable layer (flag/sum casts, LIKE ... ESCAPE '!', LIMIT/OFFSET binds).
  Run scripts/api-smoke.py against a MySQL staging copy before going live.

End-to-end:
- scripts/api-smoke.py against PostgreSQL and SQLite: 0 failures
- DKIM keys/signing, fetchmail, TOTP setup + TOTP login, TOTP exceptions,
  application passwords against PostgreSQL: PASS
- Browser run (Chromium/Playwright) as global admin, domain admin and mailbox
  user, English and Polish, desktop and phone width: no JavaScript errors,
  no horizontal page overflow on phones.