fix: exclude derived subscribe completion field

app/api/endpoints/subscribe.py

@@ -92,6 +92,8 @@ async def create_subscribe(
     subscribe_dict = subscribe_in.model_dump()
     if subscribe_in.id:
         subscribe_dict.pop("id", None)
+    # completed_episode 是响应派生字段，禁止写入持久层
+    subscribe_dict.pop("completed_episode", None)
     sid, message = await SubscribeChain().async_add(
         mtype=mtype, title=title, exist_ok=True, **subscribe_dict
     )

tests/test_subscribe_endpoint.py

@@ -0,0 +1,44 @@
+import asyncio
+from types import SimpleNamespace
+from unittest import TestCase
+from unittest.mock import AsyncMock, patch
+
+from app.api.endpoints.subscribe import create_subscribe
+from app.schemas.subscribe import Subscribe
+from app.schemas.types import MediaType
+
+
+class SubscribeEndpointTest(TestCase):
+    """
+    订阅接口回归测试。
+    """
+
+    def test_create_subscribe_excludes_completed_episode_from_write_payload(self):
+        """
+        新增订阅时不应把 completed_episode 派生字段传入持久化链路。
+        """
+        subscribe_in = Subscribe(
+            name="测试剧集",
+            year="2026",
+            type=MediaType.TV.value,
+            season=1,
+            total_episode=10,
+            lack_episode=3,
+        )
+
+        self.assertEqual(subscribe_in.completed_episode, 7)
+
+        with patch(
+            "app.api.endpoints.subscribe.SubscribeChain.async_add",
+            new=AsyncMock(return_value=(1, "新增订阅成功")),
+        ) as async_add:
+            response = asyncio.run(
+                create_subscribe(
+                    subscribe_in=subscribe_in,
+                    current_user=SimpleNamespace(name="moviepilot-user"),
+                )
+            )
+
+        self.assertTrue(response.success)
+        self.assertNotIn("completed_episode", async_add.await_args.kwargs)
+        self.assertEqual(async_add.await_args.kwargs["username"], "moviepilot-user")