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/data/repositories/goals_repository.dart

@@ -69,6 +69,21 @@ class GoalsRepository {
     }
   }
 
+  Future<bool> canModifyGoals(String userId) async {
+    try {
+      final response = await _client
+          .from('users')
+          .select('countdown_start_date')
+          .eq('id', userId)
+          .single();
+
+      final countdownStartDate = response['countdown_start_date'];
+      return countdownStartDate == null;
+    } catch (e) {
+      throw _handleError(e);
+    }
+  }
+
   Future<void> deleteGoal(String goalId) async {
     try {
       await _client.from('goals').delete().eq('id', goalId);