feat: complete T-530 cmhub URL normalization

tests/test_ai.py

@@ -516,6 +516,28 @@ class AITests(TempDirMixin, unittest.TestCase):
         self.assertEqual("https://cmhub.example.com/api/v1/models", calls[0][1])
         self.assertEqual("title-standard", models[0]["alias"])
 
+    def test_fetch_cmhub_models_404_returns_clear_base_url_error(self):
+        calls = []
+
+        def fake_request(method, url, **kwargs):
+            calls.append((method, url, kwargs))
+            return _RequestsResponse({"detail": "notfound"}, status_code=404)
+
+        with mock.patch("app.ai.requests.request", side_effect=fake_request):
+            with self.assertRaises(ai.CMHubError) as raised:
+                ai.fetch_cmhub_models(
+                    "https://cmhub.example.com/api/v1/",
+                    "sk-cmhub-secret",
+                )
+
+        self.assertEqual("GET", calls[0][0])
+        self.assertEqual("https://cmhub.example.com/api/v1/models", calls[0][1])
+        self.assertEqual("not_found", raised.exception.code)
+        self.assertEqual(404, raised.exception.status)
+        message = str(raised.exception)
+        self.assertIn("cmhub 接口不存在", message)
+        self.assertIn("/api/v1/models", message)
+        self.assertNotIn("notfound", message)
     def test_fetch_cmhub_balance_returns_points(self):
         calls = []