feat: add OCR and Excel SF9/SF10 enrollment auto-update with teacher validation and semester deduplication

frontend/lib/domain/repositories/settings_repository.dart

@@ -0,0 +1,48 @@
+import 'package:dio/dio.dart';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import '../../core/network/api_constants.dart';
+
+class SettingsRepository {
+  final Dio _dio = ApiConstants.createDio();
+  final FlutterSecureStorage _storage = const FlutterSecureStorage();
+
+  Future<Options> _getAuthOptions() async {
+    _dio.options.baseUrl = ApiConstants.baseUrl;
+    final token = await _storage.read(key: 'jwt_token');
+    return Options(headers: {'Authorization': 'Bearer $token'});
+  }
+
+  Future<Map<String, String>> getSettings() async {
+    try {
+      final options = await _getAuthOptions();
+      final response = await _dio.get('/settings', options: options);
+      final data = response.data;
+      if (data != null && data['data'] != null) {
+        final map = data['data'] as Map<String, dynamic>;
+        return map.map((key, value) => MapEntry(key, value.toString()));
+      }
+      return {'auto_update_enrollment_from_sf': 'true'};
+    } catch (e) {
+      return {'auto_update_enrollment_from_sf': 'true'};
+    }
+  }
+
+  Future<Map<String, String>> updateSettings(Map<String, String> updates) async {
+    try {
+      final options = await _getAuthOptions();
+      final response = await _dio.put(
+        '/settings',
+        data: {'settings': updates},
+        options: options,
+      );
+      final data = response.data;
+      if (data != null && data['data'] != null) {
+        final map = data['data'] as Map<String, dynamic>;
+        return map.map((key, value) => MapEntry(key, value.toString()));
+      }
+      return updates;
+    } catch (e) {
+      rethrow;
+    }
+  }
+}