Address the seven findings from the security & deployment review.
High:
- upload: make infer authoritative — reject files it can't identify
(SVG/HTML/JS) and require the detected MIME to be on an ALLOWED_MEDIA
allowlist; derive the stored MIME and on-disk extension from the
detected type, ignoring client filename/Content-Type. Closes the
stored-XSS vector via media served on-origin.
- deploy: rename docker-compose.override.yml -> docker-compose.dev.yml
so the default `docker compose up -d` no longer publishes Postgres
5432 to the host; the port map is now opt-in via -f. README updated.
Medium:
- upload: DefaultBodyLimit::disable() -> max(576 MiB) as an HTTP-level
OOM backstop; handler still enforces precise per-class size limits.
- docker: run backend and frontend as non-root users.
Low:
- social/upload: event-scope toggle_like, list_comments, add_comment,
delete_comment, edit_upload, delete_upload via find_by_id_and_event /
soft_delete_in_event — cross-event IDs now resolve to 404.
- Caddy: site-wide HSTS / nosniff / X-Frame-Options / Referrer-Policy,
plus Content-Disposition: attachment on /media/originals/*.
- .env.example: replace default Postgres password with a CHANGE_ME hint.
Out of scope: localStorage JWT (root cause fixed; httpOnly cookies are a
larger change tracked separately).
Verified: cargo build (no new warnings), cargo test (3 passed),
caddy validate, docker compose config (no 5432 published by default).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
