feat: initial commit — Curio mastery tutor

Full Next.js App Router application with:
- AI-graded lesson checkpoints (BKT/Elo mastery tracking)
- Auth.js v5: credentials, Google, GitHub, generic OIDC
- Anonymous-session-first with migrate-on-signin
- Admin panel: users, blueprints, reports, site settings
- Password reset + email verification (nodemailer/SMTP)
- Site config: require_auth + signups_enabled flags
- server-only guards on all DB/generation/verification modules
- PostgreSQL 16 + pgvector, Redis cache, Drizzle ORM
- 271 unit tests (Vitest), golden-eval harness, Playwright e2e stubs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

jobs/index.ts

@@ -0,0 +1,17 @@
+import generateLessonWorker from './generate-lesson-job';
+import promoteBlueprintWorker from './promote-blueprint-job';
+
+console.log('[workers] Running: generate-lesson, promote-blueprint');
+
+async function shutdown(signal: string) {
+  console.log(`[workers] ${signal} received — draining and closing workers...`);
+  await Promise.all([
+    generateLessonWorker.close(),
+    promoteBlueprintWorker.close(),
+  ]);
+  console.log('[workers] Shutdown complete.');
+  process.exit(0);
+}
+
+process.on('SIGTERM', () => void shutdown('SIGTERM'));
+process.on('SIGINT',  () => void shutdown('SIGINT'));