fix: seed production defaults and harden onboarding

frontend/test/visual_contract_test.dart

@@ -65,9 +65,12 @@ void main() {
     ).readAsStringSync();
     final addPage = File('lib/features/add/add_page.dart').readAsStringSync();
     final chat = File('lib/features/chat/chat_page.dart').readAsStringSync();
-    final companion = File(
-      'lib/features/settings/companion_page.dart',
-    ).readAsStringSync();
+    final companion = File(
+      'lib/features/settings/companion_page.dart',
+    ).readAsStringSync();
+    final onboarding = File(
+      'lib/features/onboarding/pages/onboarding_page.dart',
+    ).readAsStringSync();
     final me = File('lib/features/settings/me_page.dart').readAsStringSync();
     final report = File(
       'lib/features/stats/report_page.dart',
@@ -76,13 +79,30 @@ void main() {
     expect(controls, contains(': context.jz.card'));
     expect(addPage, isNot(contains('selected ? _activeColor : Colors.white')));
     expect(chat, isNot(contains('isMe ? AppTheme.primary : Colors.white')));
-    expect(
-      companion,
-      isNot(contains('context.jz.aiBackground : Colors.white')),
-    );
+    expect(
+      companion,
+      isNot(contains('context.jz.aiBackground : Colors.white')),
+    );
+    expect(onboarding, contains(': context.jz.card'));
+    expect(
+      onboarding,
+      isNot(contains('context.jz.aiBackground : Colors.white')),
+    );
     expect(me, isNot(contains('context.jz.primaryBackground : Colors.white')));
-    expect(report, isNot(contains('selected ? Colors.white')));
-  });
+    expect(report, isNot(contains('selected ? Colors.white')));
+  });
+
+  test('首次引导只提交服务端实际返回的 AI 伙伴配置', () {
+    final onboarding = File(
+      'lib/features/onboarding/pages/onboarding_page.dart',
+    ).readAsStringSync();
+
+    expect(onboarding, contains('_hasValidCatalogSelection'));
+    expect(onboarding, contains('AI 伙伴配置暂不可用'));
+    expect(onboarding, contains('重新加载'));
+    expect(onboarding, isNot(contains('_fallbackAvatars')));
+    expect(onboarding, isNot(contains('_fallbackPersonas')));
+  });
 
   test('聊天附件只保留拍照和相册导入', () {
     final source = File('lib/features/chat/chat_page.dart').readAsStringSync();