feat: Complete Phase 1 Authentication and setup Flutter project structure

- Completed authentication system with signup, login, password reset, and logout
- Enhanced error handling and accessibility across all auth flows
- Added comprehensive loading states and user feedback
- Implemented confirmation dialogs for destructive actions
- Setup complete Flutter project structure with proper configuration
- Added planning documentation for Phase 2 household creation
- All Phase 1 success criteria verified and complete

test/integration_test/auth_flow_test.dart

@@ -0,0 +1,144 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:integration_test/integration_test.dart';
+import 'package:go_router/go_router.dart';
+
+import 'package:sage/main.dart' as app;
+import 'package:sage/core/router/app_router.dart';
+
+/// Integration test for password reset flow
+/// 
+/// Tests the complete password reset journey:
+/// 1. Navigate to password reset from login
+/// 2. Request password reset
+/// 3. Handle deep link with token
+/// 4. Update password
+/// 5. Navigate back to login
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  group('Password Reset Flow', () {
+    testWidgets('complete password reset flow works correctly', (WidgetTester tester) async {
+      // Launch app
+      app.main();
+      await tester.pumpAndSettle();
+
+      // Start from login screen (if not already there)
+      // Navigate to password reset
+      final forgotPasswordButton = find.text('Forgot Password?');
+      expect(forgotPasswordButton, findsOneWidget);
+      
+      await tester.tap(forgotPasswordButton);
+      await tester.pumpAndSettle();
+
+      // Should be on reset password page
+      expect(find.text('Reset Password'), findsOneWidget);
+      expect(find.text('Forgot Password?'), findsOneWidget);
+      
+      // Test deep linking by simulating URL with token
+      // This would normally be triggered by email link
+      final context = tester.element(find.byType(Scaffold));
+      
+      // Navigate to reset password confirm with token
+      GoRouter.of(context).go('/reset-password-confirm?token=test123&email=test@example.com');
+      await tester.pumpAndSettle();
+      
+      // Should be on reset password confirm page
+      expect(find.text('Reset Password'), findsOneWidget);
+      
+      // Navigate to update password with token
+      GoRouter.of(context).go('/update-password?token=test123&email=test@example.com');
+      await tester.pumpAndSettle();
+      
+      // Should be on update password page
+      expect(find.text('Update Password'), findsOneWidget);
+      expect(find.text('Set New Password'), findsOneWidget);
+    });
+
+    testWidgets('password reset navigation from signup works', (WidgetTester tester) async {
+      // Launch app
+      app.main();
+      await tester.pumpAndSettle();
+
+      // Navigate to signup first
+      final signupButton = find.text('Sign Up');
+      if (signupButton.evaluate().isNotEmpty) {
+        await tester.tap(signupButton);
+        await tester.pumpAndSettle();
+      }
+
+      // Look for forgot password link on signup page
+      final signupForgotPassword = find.text('Forgot Password?');
+      expect(signupForgotPassword, findsOneWidget);
+      
+      await tester.tap(signupForgotPassword);
+      await tester.pumpAndSettle();
+
+      // Should navigate to reset password page
+      expect(find.text('Reset Password'), findsOneWidget);
+      expect(find.text('Forgot Password?'), findsOneWidget);
+    });
+
+    testWidgets('deep linking handles malformed URLs gracefully', (WidgetTester tester) async {
+      // Launch app
+      app.main();
+      await tester.pumpAndSettle();
+
+      // Test malformed reset URL
+      final context = tester.element(find.byType(Scaffold));
+      GoRouter.of(context).go('/reset-password-invalid');
+      await tester.pumpAndSettle();
+
+      // Should show error page with option to request new reset
+      expect(find.text('Page not found'), findsOneWidget);
+      expect(find.text('Request New Reset Link'), findsOneWidget);
+    });
+
+    testWidgets('router extracts URL parameters correctly', (WidgetTester tester) async {
+      // Launch app
+      app.main();
+      await tester.pumpAndSettle();
+
+      // Navigate with URL parameters
+      final context = tester.element(find.byType(Scaffold));
+      GoRouter.of(context).go('/reset-password-confirm?token=abc123&email=user@example.com');
+      await tester.pumpAndSettle();
+
+      // Extract parameters using router helper
+      final params = AppRouter.extractQueryParameters(context);
+      expect(params['token'], 'abc123');
+      expect(params['email'], 'user@example.com');
+      
+      // Test deep link handler
+      final resetData = AppRouter.handlePasswordResetDeepLink(context);
+      expect(resetData['token'], 'abc123');
+      expect(resetData['email'], 'user@example.com');
+    });
+  });
+
+  group('Navigation Guards', () {
+    testWidgets('password reset routes are accessible without auth', (WidgetTester tester) async {
+      // Launch app
+      app.main();
+      await tester.pumpAndSettle();
+
+      // Test all password reset routes are accessible
+      final context = tester.element(find.byType(Scaffold));
+      
+      // Test /reset-password
+      GoRouter.of(context).go('/reset-password');
+      await tester.pumpAndSettle();
+      expect(find.text('Reset Password'), findsOneWidget);
+      
+      // Test /reset-password-confirm
+      GoRouter.of(context).go('/reset-password-confirm');
+      await tester.pumpAndSettle();
+      expect(find.text('Reset Password'), findsOneWidget);
+      
+      // Test /update-password
+      GoRouter.of(context).go('/update-password');
+      await tester.pumpAndSettle();
+      expect(find.text('Update Password'), findsOneWidget);
+    });
+  });
+}