feat: consolidate backend and docker-compose setup

lib/features/auth/auth_provider.dart

@@ -0,0 +1,51 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import '../../core/network/api_client.dart';
+import '../../config/app_config.dart';
+
+class AuthNotifier extends StateNotifier<bool> {
+  AuthNotifier() : super(false);
+
+  Future<bool> checkLoginState() async {
+    final prefs = await SharedPreferences.getInstance();
+    final token = prefs.getString('auth_token');
+    if (token != null) {
+      state = true;
+      return true;
+    }
+    state = false;
+    return false;
+  }
+
+  Future<void> login(String username, String password) async {
+    final apiClient = ApiClient();
+    try {
+      final response = await apiClient.client.post(
+        AppConfig.loginEndpoint,
+        data: {
+          'username': username,
+          'password': password,
+        },
+      );
+      
+      final token = response.data['data']['token'];
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setString('auth_token', token);
+      
+      state = true;
+    } catch (e) {
+      state = false;
+      rethrow;
+    }
+  }
+
+  Future<void> logout() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.remove('auth_token');
+    state = false;
+  }
+}
+
+final authProvider = StateNotifierProvider<AuthNotifier, bool>((ref) {
+  return AuthNotifier();
+});