feat: Complete Phase 1 - Full Flutter app implementation with comprehensive features

Version: 1.1.0

Major changes:
- Implemented complete Flutter app structure with all core features
- Added comprehensive UI screens for auth, countdown, goals, profile, settings, and social features
- Integrated Supabase backend with authentication and data repositories
- Added offline support with Hive caching and local storage
- Implemented comprehensive routing with go_router
- Added location services with Google Maps integration
- Implemented notifications and home widget support
- Added voice recording capabilities and AI chat features
- Created comprehensive test suite and documentation
- Added Android and iOS platform configurations
- Implemented achievements system and social features
- Added calendar integration and bucket list functionality

This represents a complete Phase 1 milestone with 3,775 additions across 31 files.

lifetimer/lib/features/social/presentation/social_feed_screen.dart

@@ -1,16 +1,160 @@
-import 'package:flutter/material.dart';
+// ignore_for_file: deprecated_member_use
 
-class SocialFeedScreen extends StatelessWidget {
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../../../core/widgets/app_scaffold.dart';
+import '../../../core/widgets/bottom_nav_scaffold.dart';
+import '../../../core/widgets/loading_indicator.dart';
+import '../../../core/widgets/empty_state.dart';
+import '../../../core/utils/date_time_utils.dart';
+import '../../../data/models/activity_model.dart';
+import '../../auth/application/auth_controller.dart';
+import '../application/social_controller.dart';
+
+class SocialFeedScreen extends ConsumerStatefulWidget {
   const SocialFeedScreen({super.key});
 
+  @override
+  ConsumerState<SocialFeedScreen> createState() => _SocialFeedScreenState();
+}
+
+class _SocialFeedScreenState extends ConsumerState<SocialFeedScreen> {
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _loadFeed();
+    });
+  }
+
+  Future<void> _loadFeed() async {
+    final authController = ref.read(authControllerProvider.notifier);
+    final userId = authController.currentUserId;
+    if (userId != null) {
+      await ref.read(socialControllerProvider.notifier).loadActivityFeed(userId);
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Social'),
+    final socialState = ref.watch(socialControllerProvider);
+
+    return BottomNavScaffold(
+      child: AppScaffold(
+        title: 'Social Feed',
+        body: _buildBody(socialState),
       ),
-      body: const Center(
-        child: Text('Social Feed - Coming Soon'),
+    );
+  }
+
+  Widget _buildBody(SocialState state) {
+    if (state.isLoading) {
+      return const Center(child: LoadingIndicator());
+    }
+
+    if (state.error != null) {
+      return Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            const Icon(Icons.error_outline, size: 48, color: Colors.red),
+            const SizedBox(height: 16),
+            Text('Error: ${state.error}'),
+            const SizedBox(height: 16),
+            ElevatedButton(
+              onPressed: _loadFeed,
+              child: const Text('Retry'),
+            ),
+          ],
+        ),
+      );
+    }
+
+    if (state.feed == null || state.feed!.isEmpty) {
+      return const EmptyState(
+        icon: Icons.feed_outlined,
+        title: 'No Activity Yet',
+        subtitle: 'Follow users to see their progress and milestones here.',
+      );
+    }
+
+    return RefreshIndicator(
+      onRefresh: _loadFeed,
+      child: ListView.builder(
+        padding: const EdgeInsets.all(16),
+        itemCount: state.feed!.length,
+        itemBuilder: (context, index) {
+          final activity = state.feed![index];
+          return _ActivityCard(activity: activity);
+        },
+      ),
+    );
+  }
+}
+
+class _ActivityCard extends StatelessWidget {
+  final Activity activity;
+
+  const _ActivityCard({required this.activity});
+
+  @override
+  Widget build(BuildContext context) {
+    IconData icon;
+    Color iconColor;
+    String title;
+    String? subtitle;
+
+    switch (activity.type) {
+      case 'goal_completed':
+        icon = Icons.celebration;
+        iconColor = Colors.green;
+        title = 'Completed a goal!';
+        subtitle = activity.payload?['goal_title'] as String?;
+        break;
+      case 'milestone_completed':
+        icon = Icons.flag;
+        iconColor = Colors.blue;
+        title = 'Reached a milestone';
+        subtitle = activity.payload?['milestone'] as String?;
+        break;
+      case 'followed_user':
+        icon = Icons.person_add;
+        iconColor = Colors.purple;
+        title = 'Started following someone';
+        break;
+      case 'countdown_started':
+        icon = Icons.timer;
+        iconColor = Colors.orange;
+        title = 'Started their 1356-day journey!';
+        break;
+      default:
+        icon = Icons.info_outline;
+        iconColor = Colors.grey;
+        title = 'Activity';
+    }
+
+    return Card(
+      margin: const EdgeInsets.only(bottom: 12),
+      child: ListTile(
+        leading: Container(
+          width: 48,
+          height: 48,
+          decoration: BoxDecoration(
+            color: iconColor.withValues(alpha: 0.1),
+            borderRadius: BorderRadius.circular(24),
+          ),
+          child: Icon(icon, color: iconColor, size: 28),
+        ),
+        title: Text(title),
+        subtitle: subtitle != null
+            ? Text(subtitle, maxLines: 2, overflow: TextOverflow.ellipsis)
+            : null,
+        trailing: Text(
+          DateTimeUtils.formatRelativeTime(activity.createdAt),
+          style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: Theme.of(context).colorScheme.onSurfaceVariant,
+              ),
+        ),
       ),
     );
   }