fix: 修复了GET请求 SSE 泄漏的错误

src/gateway.py

@@ -620,13 +620,17 @@ async def api_jobs_stream(
     async def event_generator() -> Any:
         try:
             while True:
-                # 支持客户端主动断开
                 if await request.is_disconnected():
                     break
-                payload = await queue.get()
+                try:
+                    payload = await asyncio.wait_for(queue.get(), timeout=15)
+                except asyncio.TimeoutError:
+                    # SSE 心跳：保持连接活跃，同时让 is_disconnected() 有机会检测断开
+                    yield ": heartbeat\n\n"
+                    continue
                 yield f"data: {json.dumps(payload)}\n\n"
         except asyncio.CancelledError:
-            logger.info("Job SSE connection cancelled for user=%s", username)
+            logger.info("SSE connection cancelled for user=%s", username)
             raise
         finally:
             _unsubscribe_user_jobs(username, queue)