feat(notifications): implement notification router with email, push, SMS support

- Add notification router (sendEmail, sendPush, sendSMS, device mgmt, prefs)
- Create provider clients: Resend, Firebase Admin (FCM), Twilio
- Add notification_preferences table to Drizzle schema
- Create branded email templates (welcome, alert, password reset, family invite, billing)
- Implement notification service with error handling and E.164 validation
- Wire router into app root
- Write unit tests with mocked providers (25 tests passing)
- Add resend, firebase-admin, twilio dependencies

web/package.json

@@ -25,12 +25,15 @@
     "@typeschema/valibot": "^0.13.4",
     "bcryptjs": "^3.0.3",
     "drizzle-orm": "^0.45.2",
+    "firebase-admin": "^13.10.0",
     "jose": "^5",
     "pg": "^8.21.0",
+    "resend": "^6.12.4",
     "solid-js": "^1.9.5",
     "stripe": "^22.1.1",
     "tailwindcss": "^4.0.0",
     "three": "^0.184.0",
+    "twilio": "^6.0.2",
     "valibot": "^0.29.0",
     "vite": "^7.0.0"
   },