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/auth_repository.dart

@@ -1,11 +1,16 @@
+import 'dart:async';
+import 'package:flutter/foundation.dart' show kIsWeb;
 import '../models/user_model.dart';
 import '../../bootstrap/supabase_client.dart';
-import 'package:supabase_flutter/supabase_flutter.dart' hide User;
+import 'package:supabase_flutter/supabase_flutter.dart' as supabase;
+import 'package:google_sign_in/google_sign_in.dart';
+import 'package:sign_in_with_apple/sign_in_with_apple.dart';
 
 class AuthRepository {
-  final SupabaseClient _client;
+  final supabase.SupabaseClient _client;
+  StreamSubscription<supabase.AuthState>? _authStateSubscription;
 
-  AuthRepository([SupabaseClient? client]) : _client = client ?? supabaseClient;
+  AuthRepository([supabase.SupabaseClient? client]) : _client = client ?? supabaseClient;
 
   Stream<User?> get authStateChanges {
     return _client.auth.onAuthStateChange.map((data) {
@@ -22,6 +27,48 @@ class AuthRepository {
     return user != null ? _mapSupabaseUserToAppUser(user) : null;
   }
 
+  bool get isAuthenticated => _client.auth.currentUser != null;
+
+  String? get currentUserId => _client.auth.currentUser?.id;
+
+  Future<bool> isSessionValid() async {
+    final session = _client.auth.currentSession;
+    if (session == null) return false;
+    
+    final now = DateTime.now();
+    final expiresAt = session.expiresAt;
+    if (expiresAt == null) return true;
+    
+    return now.isBefore(DateTime.fromMillisecondsSinceEpoch(expiresAt * 1000));
+  }
+
+  Future<void> refreshSession() async {
+    try {
+      await _client.auth.refreshSession();
+    } catch (e) {
+      throw Exception('Failed to refresh session: $e');
+    }
+  }
+
+  Future<supabase.Session?> getCurrentSession() async {
+    return _client.auth.currentSession;
+  }
+
+  void listenToAuthStateChanges(Function(User?) callback) {
+    _authStateSubscription = _client.auth.onAuthStateChange.listen((data) {
+      final session = data.session;
+      if (session?.user != null) {
+        callback(_mapSupabaseUserToAppUser(session!.user));
+      } else {
+        callback(null);
+      }
+    });
+  }
+
+  void dispose() {
+    _authStateSubscription?.cancel();
+  }
+
   Future<void> signInWithEmail(String email, String password) async {
     await _client.auth.signInWithPassword(email: email, password: password);
   }
@@ -39,15 +86,58 @@ class AuthRepository {
   }
 
   Future<void> signInWithGoogle() async {
-    // TODO: Implement Google OAuth
-    // await _client.auth.signInWithOAuth(OAuthProvider.google);
-    throw UnimplementedError('Google OAuth not implemented yet');
+    final GoogleSignIn googleSignIn = GoogleSignIn();
+
+    final googleUser = await googleSignIn.signIn();
+    if (googleUser == null) {
+      throw Exception('Google sign-in was cancelled');
+    }
+
+    final googleAuth = await googleUser.authentication;
+    final idToken = googleAuth.idToken;
+
+    if (idToken == null) {
+      throw Exception('No ID token from Google sign-in');
+    }
+
+    final response = await _client.auth.signInWithIdToken(
+      provider: supabase.OAuthProvider.google,
+      idToken: idToken,
+    );
+
+    if (response.user != null) {
+      await _ensureUserProfileExists(response.user!.id, response.user!);
+    }
   }
 
   Future<void> signInWithApple() async {
-    // TODO: Implement Apple OAuth
-    // await _client.auth.signInWithOAuth(OAuthProvider.apple);
-    throw UnimplementedError('Apple OAuth not implemented yet');
+    final credential = await SignInWithApple.getAppleIDCredential(
+      scopes: [
+        AppleIDAuthorizationScopes.email,
+        AppleIDAuthorizationScopes.fullName,
+      ],
+    );
+
+    final identityToken = credential.identityToken;
+    if (identityToken == null) {
+      throw Exception('No identity token from Apple sign-in');
+    }
+
+    final response = await _client.auth.signInWithIdToken(
+      provider: supabase.OAuthProvider.apple,
+      idToken: identityToken,
+      accessToken: credential.authorizationCode,
+    );
+
+    if (response.user != null) {
+      await _ensureUserProfileExists(response.user!.id, response.user!);
+    }
+  }
+
+  Future<void> signInWithGithub() async {
+    await _client.auth.signInWithOAuth(
+      supabase.OAuthProvider.github,
+    );
   }
 
   Future<void> signOut() async {
@@ -82,7 +172,7 @@ class AuthRepository {
 
   Future<User> _createUserProfile(String userId, String username, String email) async {
     final now = DateTime.now().toIso8601String();
-    
+
     final response = await _client.from('users').insert({
       'id': userId,
       'username': username,
@@ -94,6 +184,21 @@ class AuthRepository {
     return _mapSupabaseDataToUser(response);
   }
 
+  Future<void> _ensureUserProfileExists(String userId, dynamic supabaseUser) async {
+    final existingProfile = await _client
+        .from('users')
+        .select('id')
+        .eq('id', userId)
+        .maybeSingle();
+
+    if (existingProfile == null) {
+      final username = supabaseUser.userMetadata?['username'] ??
+          'user_${userId.substring(0, 8)}';
+      final email = supabaseUser.email ?? '';
+      await _createUserProfile(userId, username, email);
+    }
+  }
+
   User _mapSupabaseUserToAppUser(dynamic supabaseUser) {
     return User(
       id: supabaseUser.id,