feat(ai): enforce direct image edit contract

tests/test_gui.py

@@ -2232,6 +2232,7 @@ class GuiTests(TempDirMixin, unittest.TestCase):
         with self.make_temp_dir() as temp_dir:
             cfg = self.make_config(temp_dir)
             models_path = cfg["ai_models_path"]
+            statuses = []
             appconfig.save_ai_models_config(
                 {
                     "models": [
@@ -2264,7 +2265,11 @@ class GuiTests(TempDirMixin, unittest.TestCase):
                 path=models_path,
             )
 
-            tab = SettingsTab(config=cfg, ai_models_path=models_path)
+            tab = SettingsTab(
+                config=cfg,
+                ai_models_path=models_path,
+                status_callback=statuses.append,
+            )
             self.addCleanup(tab.close)
 
             self.assertEqual(2, tab.model_combo.count())
@@ -2523,6 +2528,74 @@ class GuiTests(TempDirMixin, unittest.TestCase):
 
         self.assert_removed(temp_dir)
 
+    def test_settings_tab_image_model_only_offers_image_edit_and_checks_locally(self):
+        with self.make_temp_dir() as temp_dir:
+            cfg = self.make_config(temp_dir)
+            models_path = cfg["ai_models_path"]
+            statuses = []
+            appconfig.save_ai_models_config(
+                {
+                    "models": [
+                        {
+                            "name": "Text A",
+                            "category": "text",
+                            "enabled": True,
+                            "url": "https://example.invalid/v1",
+                            "model": "text-model",
+                            "api_key": "sk-text",
+                            "api_type": "chat",
+                            "connect_timeout_seconds": 30,
+                            "timeout_seconds": 0,
+                            "extra_body": {},
+                        },
+                        {
+                            "name": "Legacy Image",
+                            "category": "image",
+                            "enabled": True,
+                            "url": "https://example.invalid/v1/chat/completions",
+                            "model": "image-model",
+                            "api_key": "sk-image",
+                            "api_type": "auto",
+                            "connect_timeout_seconds": 30,
+                            "timeout_seconds": 0,
+                            "extra_body": {},
+                        },
+                    ]
+                },
+                path=models_path,
+            )
+            tab = SettingsTab(
+                config=cfg,
+                ai_models_path=models_path,
+                status_callback=statuses.append,
+            )
+            self.addCleanup(tab.close)
+            tab.model_combo.setCurrentIndex(tab.model_combo.findData("Legacy Image"))
+
+            self.assertIn("当前图片模型不支持 OpenAI 图片编辑接口", tab.model_combo.currentText())
+            self.assertEqual("auto", tab.api_type_combo.currentData())
+            self.assertEqual("检查图片配置", tab.test_connection_button.text())
+            self.assertIn("当前不支持", tab.api_type_combo.currentText())
+
+            class FakeSignal:
+                def connect(self, callback):
+                    self.callback = callback
+
+            class FakeThread:
+                def __init__(self):
+                    self.finished = FakeSignal()
+
+                def start(self):
+                    pass
+
+            with mock.patch("app.gui.run_worker", return_value=FakeThread()):
+                tab.test_connection()
+
+            self.assertTrue(tab.test_worker.check_image_config)
+            self.assertIn("正在检查图片模型配置", statuses[-1])
+
+        self.assert_removed(temp_dir)
+
     def test_settings_tab_saves_role_generation_path_and_port_config(self):
         with self.make_temp_dir() as temp_dir:
             cfg = self.make_config(temp_dir)