fix(security): critical — repair PIN reset + enforce real prod secrets

C1: reset_user_pin wrote to a non-existent column (pin_failed_attempts);
    the real column is failed_pin_attempts, so every PIN reset 500'd. Fixed
    the column name; new e2e (pin-reset.spec.ts) proves a reset returns a
    usable PIN and the target can recover with it.

C2: config.rs::validate_secrets now rejects placeholder-ish secrets
    (change_me/dev_secret/placeholder), enforces len>=32 in prod, and
    requires a real ADMIN_PASSWORD_HASH. docker-compose.yml sets
    APP_ENV=production so the guard actually runs. Corrected the false
    "fixed" claim in SECURITY-BACKLOG.md. .env.example documents the rule.

Riders in these files (documented here since git can't split hunks):
- host.rs also carries the event-scoped ban_user fix and the
  close_event/open_event no-op broadcast guard (medium).
- docker-compose.yml also adds ORIGIN (H6), app/frontend healthchecks with
  Caddy waiting on health, and per-service memory limits (medium).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/SECURITY-BACKLOG.md

@@ -51,15 +51,25 @@ item below is tagged with its **current status in `main`**:
 
 ## ✅ Fixed in main since the audit (for the record)
 
-These audit findings are present in `main` today (verified 2026-06-30): event-scoped social
-handlers (cross-event authz), server-side MIME/ext allowlist on upload, recovery-PIN lockout
-backoff, unspoofable client IP in the rate limiter, effective JWT production-secret guard, DB port
-no longer publicly exposed, container healthchecks, bcrypt offloaded via `spawn_blocking`,
-bounded compression concurrency (semaphore), bounded feed queries (`LIMIT ≤ 100`), and the
-viewport-fit / reduced-motion / aria a11y pass. **New since the audit:** an image-decode
-decompression-bomb cap (`image::Limits` 12000×12000 / 256 MiB) ported into
+These audit findings are present in `main` today (verified 2026-06-30): server-side MIME/ext
+allowlist on upload, recovery-PIN lockout backoff, DB port no longer publicly exposed, bcrypt
+offloaded via `spawn_blocking`, bounded compression concurrency (semaphore), bounded feed queries
+(`LIMIT ≤ 100`), and the viewport-fit / reduced-motion / aria a11y pass. An image-decode
+decompression-bomb cap (`image::Limits` 12000×12000 / 256 MiB) lives in
 `backend/src/services/compression.rs`.
 
+**Fixed in the 2026-07 review pass** (previously *claimed* fixed here but were not — corrected):
+- **Effective JWT production-secret guard** — `APP_ENV=production` is now set for the app service,
+  and `config.rs::validate_secrets` rejects any placeholder-ish `JWT_SECRET`/`ADMIN_PASSWORD_HASH`
+  (not just the exact dev sentinel) and enforces `len ≥ 32` unconditionally in prod.
+- **Unspoofable client IP in the rate limiter** — `client_ip` now takes the right-most
+  `X-Forwarded-For` entry (the hop Caddy appends), so a client-supplied left-most value is ignored.
+- **Live role/ban re-check** — the auth extractor re-reads the user row and trusts the DB role and
+  `is_banned` flag rather than the JWT claim, revoking demoted/banned sessions immediately.
+- **Container healthchecks** — `app` and `frontend` now have healthchecks and Caddy waits on
+  `service_healthy`.
+- **Event-scoped `ban_user`** — the ban UPDATE is now scoped by `event_id` like its siblings.
+
 ## 🅲 Consciously won't-fix at ~100-guest single-box scale
 
 Diminishing returns vs. the deployment's actual threat model. Revisit only if the scale or