Add FCM push notification support

Enable Firebase Cloud Messaging and token management plus related UI/navigation and repository fixes. Adds Firebase config and wiring (android/app/google-services.json, .firebaserc, firebase.json, lib/firebase_options.dart), Gradle plugin checks, and README instructions for setup and Supabase deployment. Implements PushNotificationService (init, background handler, permission/token handling), PushTokenRepository, and PushNotificationCoordinator (register/clear tokens on auth changes). Adds Supabase function + migration (supabase/functions/push-fcm, supabase/migrations/20260505140000_user_fcm_tokens.sql) and updates functions config. Also: include firebase_core/firebase_messaging/permission_handler deps, register background handler & optional token logging in main.dart, add mainLayout tab request provider and listener (navigation integration), improve follow repo fetching (chunked profile/pet fetch helpers) and follow controller invalidations, and refine pet followers screen validation/error messages.

Author: syed-reza98

.firebaserc

@@ -0,0 +1,5 @@
+{
+  "projects": {
+    "default": "petfolio-197e6"
+  }
+}

README.md

@@ -90,6 +90,19 @@ PetFolio is a pet social and marketplace platform that allows users to connect w
 - Mark all as read on open
 - Tap notification → navigate to relevant entity (post, order, messages)
 
+#### Push notifications (FCM, Android)
+When the app is in the background or killed, **in-app** Supabase Realtime updates stop; **Firebase Cloud Messaging** delivers system notifications instead.
+
+**Client (this repo)**  
+- After login, the app registers an FCM device token and upserts it into Supabase `user_fcm_tokens` (`lib/services/push_notification_service.dart`, `lib/repositories/push_token_repository.dart`).  
+- Android 13+ uses the existing `POST_NOTIFICATIONS` permission plus a runtime prompt via `permission_handler`.  
+- Firebase is wired for **PetFolio** (`petfolio-197e6`): `firebase.json`, `android/app/google-services.json`, and `lib/firebase_options.dart` are generated via [FlutterFire CLI](https://firebase.flutter.dev/docs/cli/configure) (`flutterfire configure --project=petfolio-197e6 …`). Re-run that command if you clone on a new machine or add iOS/Web. `google-services.json.example` remains as a template reference only.
+
+**Server (Supabase)**  
+1. Apply migration `supabase/migrations/20260505140000_user_fcm_tokens.sql` (`supabase db push` or Dashboard SQL).  
+2. Set Edge secret `FIREBASE_SERVICE_ACCOUNT_JSON` to the **minified** JSON from Firebase Console → Project settings → Service accounts → Generate new private key.  
+3. Deploy `supabase functions deploy push-fcm` and create a **Database Webhook** on `public.notifications` **INSERT** targeting that function (same pattern as [Supabase FCM guide](https://supabase.com/docs/guides/functions/examples/push-notifications?platform=fcm)).
+
 ---
 
 ### 🐕 Pet Care Diary (Core Feature)

android/app/build.gradle.kts

@@ -42,3 +42,10 @@ android {
 flutter {
     source = "../.."
 }
+
+// FCM: add `android/app/google-services.json` from Firebase Console (Android app
+// with package `com.example.pet_dating_app`). Without it, the app builds but
+// Firebase.initializeApp / device tokens will not work.
+if (file("google-services.json").exists()) {
+    apply(plugin = "com.google.gms.google-services")
+}

android/app/google-services.json

@@ -0,0 +1,29 @@
+{
+  "project_info": {
+    "project_number": "675318892178",
+    "project_id": "petfolio-197e6",
+    "storage_bucket": "petfolio-197e6.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:675318892178:android:93c1b41620e286d3bec84b",
+        "android_client_info": {
+          "package_name": "com.example.pet_dating_app"
+        }
+      },
+      "oauth_client": [],
+      "api_key": [
+        {
+          "current_key": "AIzaSyBWaGVK1Q-QQauS8EoQlAWrKrMdc4rrATQ"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": []
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

android/app/google-services.json.example

@@ -21,6 +21,7 @@ plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.9.1" apply false
     id("org.jetbrains.kotlin.android") version "2.1.0" apply false
+    id("com.google.gms.google-services") version "4.4.2" apply false
 }
 
 include(":app")

android/settings.gradle.kts

@@ -334,7 +334,7 @@ flowchart TB
 1. **Prioritize epics** E1 → E2 → E4 (or E3 first if matching is the wedge).  
 2. **Attach metrics** per epic (activation, D7 retention, GMV, care log completion rate, report rate).  
 3. **Decompose** each US into technical tasks (API, RLS policies, UI, analytics).  
-4. **Compliance review** for E5/E8 before promising clinical workflows.
+4. **Compliance review** for E5/E7 before promising clinical workflows.
 
 ---
 

docs/USER_STORIES_platform_social_matching_commerce_care.md

@@ -0,0 +1 @@
+{"flutter":{"platforms":{"android":{"default":{"projectId":"petfolio-197e6","appId":"1:675318892178:android:93c1b41620e286d3bec84b","fileOutput":"android/app/google-services.json"}},"dart":{"lib/firebase_options.dart":{"projectId":"petfolio-197e6","configurations":{"android":"1:675318892178:android:93c1b41620e286d3bec84b"}}}}}}

firebase.json

@@ -81,7 +81,9 @@ class FollowController extends Notifier<void> {
       // Invalidate related providers so the UI refreshes
       ref.invalidate(isFollowingOwnerProvider(ownerId));
       ref.invalidate(ownerFollowerCountProvider(ownerId));
+      ref.invalidate(ownerFollowersListProvider(ownerId));
       ref.invalidate(followingCountProvider(userId));
+      ref.invalidate(followingListProvider(userId));
     } catch (e) {
       debugPrint('toggleFollowOwner error: $e');
     }
@@ -127,7 +129,9 @@ class FollowController extends Notifier<void> {
       // Invalidate related providers
       ref.invalidate(isFollowingPetProvider(petId));
       ref.invalidate(petFollowerCountProvider(petId));
+      ref.invalidate(petFollowersListProvider(petId));
       ref.invalidate(followingCountProvider(userId));
+      ref.invalidate(followingListProvider(userId));
     } catch (e) {
       debugPrint('toggleFollowPet error: $e');
     }

lib/controllers/follow_controller.dart

@@ -208,3 +208,17 @@ class ProfilePetNavigation extends Notifier<String?> {
 final profilePetNavigationProvider =
     NotifierProvider<ProfilePetNavigation, String?>(
         () => ProfilePetNavigation());
+
+/// [MainLayout] listens and switches its bottom tab to the requested index
+/// (e.g. 4 for Profile), then clears the value.
+class MainLayoutTabRequest extends Notifier<int?> {
+  @override
+  int? build() => null;
+
+  void request(int index) => state = index;
+
+  void clear() => state = null;
+}
+
+final mainLayoutTabRequestProvider =
+    NotifierProvider<MainLayoutTabRequest, int?>(MainLayoutTabRequest.new);