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

apps/server/src/server.ts

@@ -17,6 +17,8 @@ import { CredentialCapture } from "./credential-capture.js";
 import { PrinterMonitor } from "./printer-monitor.js";
 import { DeviceMonitor } from "./device-monitor.js";
 import { buildSigner, buildVerifier } from "./signer.js";
+import { LogService, pinoDbStream } from "./log-service.js";
+import { logRoutes } from "./routes/logs.js";
 import { authRoutes } from "./routes/auth.js";
 import { userRoutes } from "./routes/users.js";
 import { roleRoutes } from "./routes/roles.js";
@@ -43,12 +45,20 @@ export interface BuildOptions {
 }
 
 export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInstance> {
-  const app = Fastify({
-    logger: { level: process.env.LOG_LEVEL ?? "info" },
-  });
-
+  // DB first — the logger's DB sink needs it before Fastify is constructed.
   const db = opts.db ?? createDb();
 
+  // Application-log store: a pino stream tees warn+ lines into app_logs (and still
+  // writes them to stdout), so backend warnings/errors are queryable from the booth
+  // alongside frontend errors. See log-service.ts + wiki/concepts/app-logs.md.
+  const logService = new LogService(db);
+  const app = Fastify({
+    logger: {
+      level: process.env.LOG_LEVEL ?? "info",
+      stream: pinoDbStream(logService, process.stdout),
+    },
+  });
+
   // Wire the RBAC permission resolver to this DB (route guards resolve a user's
   // role → permission set through it). See auth.ts.
   initAuth(db);
@@ -188,6 +198,20 @@ export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInsta
   // at capacity) is in the entry flow. See wiki/concepts/capacity-occupancy.md.
   await siteRoutes(app, db);
 
+  // Application logs: ingest frontend errors (POST /api/logs, any signed-in user) +
+  // read the store (GET /api/logs, log:read). See wiki/concepts/app-logs.md.
+  await logRoutes(app, logService);
+
+  // Periodic retention prune (age + row cap) so the log table stays bounded on the
+  // offline appliance. Runs hourly; unref'd so it never holds the process open.
+  const pruneTimer = setInterval(() => {
+    const n = logService.prune();
+    if (n > 0) app.log.debug(`pruned ${n} app_log rows`);
+  }, 60 * 60 * 1000);
+  pruneTimer.unref();
+  logService.prune(); // once at startup
+  app.addHook("onClose", async () => clearInterval(pruneTimer));
+
   const unsubscribeInput = deviceEvents.onInput((e) => {
     // Record every input edge as unsigned telemetry, keyed to the device that fired
     // (provenance). No lane — the pool-of-spaces model has none. The entry flow