feat(logs): app log store — backend pino DB sink + frontend error collection

Add a third data stream (app_logs), distinct from the signed ledger and device
telemetry, for operational/diagnostic logs — an offline appliance has no Sentry to
ship to, so the host is the log store.

Backend: a pino stream tees warn/error/fatal into app_logs (info/debug stay
stdout-only) with no call-site change; the DB is built before Fastify so the logger
has its sink. Frontend (lib/logger.ts): ships failed API requests (minus 401 churn),
window.onerror, unhandledrejection, and a top-level React ErrorBoundary; console
warn/error forwarded only at debug/trace. Batched/throttled POST, sendBeacon on
pagehide, loop-safe (never logs the /api/logs call), best-effort everywhere.

POST /api/logs (any signed-in user, CSRF, tolerant) + GET /api/logs gated by a new
log:read permission (new `log` RBAC resource; admin holds it). Retention: pruned by
age + row cap, hourly + at startup. UI: a Logs screen under /setup (filter
level/source/since, expand to context+stack), sq+en. Migration 0009_app_logs.

Verified end-to-end via app.inject: login -> POST 204 -> GET 200 with the record;
backend warn/error persisted, info dropped; non-admin GET 403 / POST 204.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

wiki/concepts/device-events.md

@@ -31,6 +31,11 @@ diagnostics, and live booth status — **not** anti-fraud.
 - **Device-keyed** — references the `devices` instance (raw device provenance). No `lane`
   (pool-of-spaces model — see [[entry-exit-points]]).
 
+> **Not to be confused with [[app-logs]].** `device_events` is **hardware telemetry** (a relay fired,
+> a camera failed). Diagnostic/application logs (a failed API request, an uncaught frontend error,
+> a backend warning) are a **separate third stream** in `app_logs` — don't route app errors here, nor
+> hardware telemetry there. Both are unsigned + prunable; the distinction is *what produced it*.
+
 ## The boundary that matters
 
 A device event is *evidence the host saw something happen*; it does **not** by itself authorize or