feat: enforce iOS AI safety policy and citations

health_app/lib/core/api_client.dart

@@ -9,9 +9,22 @@ const String baseUrl = String.fromEnvironment(
   'API_BASE_URL',
   defaultValue: kReleaseMode
       ? 'https://erpapi.datalumina.cn/xiaomai'
-      : 'http://10.4.225.209:5000',
+      : 'http://10.4.232.91:5000',
 );
 
+const String _configuredAppPolicy = String.fromEnvironment(
+  'APP_POLICY_PROFILE',
+  defaultValue: '',
+);
+
+String get appPolicyProfile {
+  if (_configuredAppPolicy == 'android-standard' ||
+      _configuredAppPolicy == 'ios-medical-citations') {
+    return _configuredAppPolicy;
+  }
+  return Platform.isIOS ? 'ios-medical-citations' : 'android-standard';
+}
+
 class ApiException implements Exception {
   final int? code;
   final String message;
@@ -56,7 +69,10 @@ class ApiClient {
            baseUrl: baseUrl,
            connectTimeout: const Duration(seconds: 15),
            receiveTimeout: const Duration(seconds: 60),
-           headers: {'Content-Type': 'application/json'},
+           headers: {
+             'Content-Type': 'application/json',
+             'X-App-Policy': appPolicyProfile,
+           },
          ),
        ) {
     _dio.interceptors.add(_AuthInterceptor(this));