feat: 完成T-501设置页AI模型管理

- 新增SettingsTab，接入AI模型下拉、新增、删除、详情编辑和保存

- 新增AIModelTestWorker，后台调用appconfig.test_ai_model测试连接

- 密钥输入使用密码框打码，删除保护保持text/image模型类别约束

- 补充GUI测试覆盖模型加载、保存删除和测试连接worker

- 同步任务看板、current-state、routes、api和progress

tests/test_gui.py

@@ -9,7 +9,7 @@ sys.path.insert(0, os.path.dirname(__file__))
 from _helpers import TempDirMixin
 
 from app import gui
-from app import accounts, db, prompts
+from app import accounts, appconfig, db, prompts
 
 if gui.QT_IMPORT_ERROR is not None:
     raise unittest.SkipTest("PySide6 未安装")
@@ -20,6 +20,7 @@ from PySide6.QtWidgets import QApplication, QLineEdit, QPlainTextEdit, QTableVie
 from app.gui import (
     AccountDialog,
     AccountsTab,
+    AIModelTestWorker,
     ApplyTab,
     ApplyWorker,
     CollectWorker,
@@ -27,6 +28,7 @@ from app.gui import (
     GenerateWorker,
     GenerateTab,
     MainWindow,
+    SettingsTab,
     TAB_STYLE,
     TAB_TITLES,
     WriteBackWorker,
@@ -51,6 +53,7 @@ class GuiTests(TempDirMixin, unittest.TestCase):
             "image_dir": os.path.join(temp_dir, "images"),
             "db_path": os.path.join(temp_dir, "cmshopee.db"),
             "debug_port_range": [9222, 9260],
+            "ai_models_path": os.path.join(temp_dir, "ai_models.json"),
         }
 
     def test_main_window_has_five_tabs_in_workflow_order(self):
@@ -71,6 +74,7 @@ class GuiTests(TempDirMixin, unittest.TestCase):
             self.assertIsInstance(window.tabs.widget(0), CollectTab)
             self.assertIsInstance(window.tabs.widget(1), GenerateTab)
             self.assertIsInstance(window.tabs.widget(2), ApplyTab)
+            self.assertIsInstance(window.tabs.widget(4), SettingsTab)
             self.assertEqual(
                 "回写旧数据到 Excel",
                 window.tabs.widget(0).write_back_button.text(),
@@ -78,6 +82,155 @@ class GuiTests(TempDirMixin, unittest.TestCase):
 
         self.assert_removed(temp_dir)
 
+    def test_settings_tab_loads_ai_models_and_masks_key_field(self):
+        with self.make_temp_dir() as temp_dir:
+            cfg = self.make_config(temp_dir)
+            models_path = cfg["ai_models_path"]
+            appconfig.save_ai_models_config(
+                {
+                    "models": [
+                        {
+                            "name": "Text A",
+                            "category": "text",
+                            "enabled": True,
+                            "url": "https://example.invalid/text",
+                            "model": "text-model",
+                            "api_key": "sk-text-secret",
+                            "api_type": "chat",
+                            "connect_timeout_seconds": 11,
+                            "timeout_seconds": 0,
+                            "extra_body": {"temperature": 0},
+                        },
+                        {
+                            "name": "Image A",
+                            "category": "image",
+                            "enabled": True,
+                            "url": "https://example.invalid/image",
+                            "model": "image-model",
+                            "api_key": "sk-image-secret",
+                            "api_type": "auto",
+                            "connect_timeout_seconds": 22,
+                            "timeout_seconds": 0,
+                            "extra_body": {},
+                        },
+                    ]
+                },
+                path=models_path,
+            )
+
+            tab = SettingsTab(config=cfg, ai_models_path=models_path)
+            self.addCleanup(tab.close)
+
+            self.assertEqual(2, tab.model_combo.count())
+            self.assertEqual("Text A", tab.name_edit.text())
+            self.assertEqual("text", tab.category_combo.currentData())
+            self.assertEqual("chat", tab.api_type_combo.currentData())
+            self.assertEqual("text-model", tab.model_id_edit.text())
+            self.assertEqual("https://example.invalid/text", tab.url_edit.text())
+            self.assertEqual("sk-text-secret", tab.api_key_edit.text())
+            self.assertEqual(QLineEdit.Password, tab.api_key_edit.echoMode())
+            self.assertEqual(11, tab.connect_timeout_spin.value())
+            self.assertFalse(tab.delete_model_button.isEnabled())
+
+        self.assert_removed(temp_dir)
+
+    def test_settings_tab_adds_saves_and_deletes_model(self):
+        with self.make_temp_dir() as temp_dir:
+            cfg = self.make_config(temp_dir)
+            models_path = cfg["ai_models_path"]
+            statuses = []
+            tab = SettingsTab(
+                config=cfg,
+                ai_models_path=models_path,
+                status_callback=statuses.append,
+            )
+            self.addCleanup(tab.close)
+
+            tab.add_model()
+            self.assertEqual("新文本模型", tab.current_model_name)
+            self.assertEqual(3, tab.model_combo.count())
+
+            tab.name_edit.setText("Text Custom")
+            tab.url_edit.setText("https://example.invalid/v1/chat/completions")
+            tab.model_id_edit.setText("demo-text")
+            tab.api_key_edit.setText("sk-custom-secret")
+            tab.api_type_combo.setCurrentIndex(tab.api_type_combo.findData("chat"))
+            tab.connect_timeout_spin.setValue(12)
+            tab.save_model()
+
+            saved = appconfig.get_model("Text Custom", path=models_path)
+            self.assertEqual("text", saved["category"])
+            self.assertEqual("demo-text", saved["model"])
+            self.assertEqual("sk-custom-secret", saved["api_key"])
+            self.assertEqual(12, saved["connect_timeout_seconds"])
+            self.assertIn("AI 模型已保存：Text Custom", statuses[-1])
+            self.assertTrue(tab.delete_model_button.isEnabled())
+
+            with mock.patch("app.gui.QMessageBox.question", return_value=gui.QMessageBox.Yes):
+                tab.delete_model()
+
+            names = [model["name"] for model in appconfig.list_ai_models(path=models_path)]
+            self.assertNotIn("Text Custom", names)
+            self.assertIn("AI 模型已删除：Text Custom", statuses[-1])
+
+        self.assert_removed(temp_dir)
+
+    def test_settings_tab_starts_connection_test_worker(self):
+        with self.make_temp_dir() as temp_dir:
+            cfg = self.make_config(temp_dir)
+            models_path = cfg["ai_models_path"]
+            statuses = []
+            tab = SettingsTab(
+                config=cfg,
+                ai_models_path=models_path,
+                status_callback=statuses.append,
+            )
+            self.addCleanup(tab.close)
+
+            class FakeSignal:
+                def __init__(self):
+                    self.callbacks = []
+
+                def connect(self, callback):
+                    self.callbacks.append(callback)
+
+            class FakeThread:
+                def __init__(self):
+                    self.finished = FakeSignal()
+                    self.started = False
+
+                def start(self):
+                    self.started = True
+
+            fake_thread = FakeThread()
+            with mock.patch("app.gui.run_worker", return_value=fake_thread) as run_worker:
+                tab.test_connection()
+
+            run_worker.assert_called_once()
+            self.assertIsInstance(tab.test_worker, AIModelTestWorker)
+            self.assertIs(tab.test_thread, fake_thread)
+            self.assertTrue(fake_thread.started)
+            self.assertFalse(tab.test_connection_button.isEnabled())
+            self.assertIn("正在测试 AI 模型连接", statuses[-1])
+
+        self.assert_removed(temp_dir)
+
+    def test_ai_model_test_worker_calls_appconfig(self):
+        with self.make_temp_dir() as temp_dir:
+            models_path = os.path.join(temp_dir, "ai_models.json")
+            worker = AIModelTestWorker("Text A", ai_models_path=models_path)
+
+            with mock.patch(
+                "app.gui.appconfig.test_ai_model",
+                return_value={"ok": True, "status": 200},
+            ) as test_ai_model:
+                result = worker.execute()
+
+            test_ai_model.assert_called_once_with("Text A", path=models_path)
+            self.assertEqual({"ok": True, "status": 200, "name": "Text A"}, result)
+
+        self.assert_removed(temp_dir)
+
     def test_generate_tab_has_prompt_editors_and_task_table(self):
         with self.make_temp_dir() as temp_dir:
             title_prompt_path = os.path.join(temp_dir, "title_prompt.txt")