Complete Firebase setup with Data Connect and security rules

- Initialize Firebase Data Connect
- Deploy Firestore security rules for SMTP config
- Update firebase.json with Firestore configuration
- Add generated Data Connect SDKs

package.json

@@ -9,6 +9,7 @@
     "lint": "eslint"
   },
   "dependencies": {
+    "@dataconnect/generated": "file:src/dataconnect-generated",
     "firebase": "^12.4.0",
     "next": "16.0.0",
     "next-pwa": "^5.6.0",