feat: scope filterable fields to agent type and update active filters on selection change

lib/features/agents/data/agents_repository.dart

@@ -89,10 +89,16 @@ class AgentsRepository {
   }
 
   /// Get filterable profile fields: GET /profile-fields/filterable
+  /// When `agentTypeId` is provided, backend scopes filters to that agent type + globals.
   /// Response: { success, data: [...] }
-  Future<List<FilterableField>> getFilterableFields() async {
+  Future<List<FilterableField>> getFilterableFields({String? agentTypeId}) async {
     try {
-      final response = await _dio.get(ApiConstants.filterableFields);
+      final response = await _dio.get(
+        ApiConstants.filterableFields,
+        queryParameters: agentTypeId != null && agentTypeId.isNotEmpty
+            ? {'agentTypeId': agentTypeId}
+            : null,
+      );
       final data = response.data['data'] as List<dynamic>;
       return data
           .map((e) => FilterableField.fromJson(e as Map<String, dynamic>))