debug: add loop exit logging to terminal WebSocket handler

apps/api/src/api/terminal.py

@@ -97,6 +97,11 @@ async def terminal_websocket(
             return_when=asyncio.FIRST_COMPLETED,
         )
         
+        # Log which task completed
+        for task in done:
+            task_name = "read" if task == read_task else "write" if task == write_task else "heartbeat"
+            logger.info(f"Task '{task_name}' completed first for instance {instance_id}")
+        
         # Cancel remaining tasks
         for task in pending:
             task.cancel()
@@ -116,24 +121,35 @@ async def terminal_websocket(
 
 async def _read_loop(session, websocket) -> None:
     """Read output from the container and send to WebSocket."""
+    loop_count = 0
     try:
         while session.is_alive() and not session._closed:
+            loop_count += 1
+            if loop_count == 1:
+                logger.info(f"Read loop started for session {session.session_id}, alive={session.is_alive()}, closed={session._closed}")
             data = await session.read_output()
             if data:
                 try:
                     await websocket.send_bytes(data)
-                except Exception:
+                except Exception as e:
+                    logger.warning(f"Read loop send_bytes failed: {e}")
                     break
             else:
                 await asyncio.sleep(0.01)
-    except Exception:
+    except Exception as e:
-        pass
+        logger.warning(f"Read loop exception: {e}")
+    finally:
+        logger.info(f"Read loop exited after {loop_count} iterations, alive={session.is_alive()}, closed={session._closed}")
 
 
 async def _write_loop(session, websocket) -> None:
     """Read input from WebSocket and send to container."""
+    loop_count = 0
     try:
         while session.is_alive() and not session._closed:
+            loop_count += 1
+            if loop_count == 1:
+                logger.info(f"Write loop started for session {session.session_id}, alive={session.is_alive()}, closed={session._closed}")
             message = await websocket.receive()
             if message["type"] == "websocket.receive":
                 if "bytes" in message:
@@ -177,9 +193,12 @@ async def _write_loop(session, websocket) -> None:
                     else:
                         await session.write_input(text.encode("utf-8"))
             elif message["type"] == "websocket.disconnect":
+                logger.info(f"Write loop: websocket.disconnect received for session {session.session_id}")
                 break
-    except Exception:
+    except Exception as e:
-        pass
+        logger.warning(f"Write loop exception for session {session.session_id}: {e}")
+    finally:
+        logger.info(f"Write loop exited after {loop_count} iterations, alive={session.is_alive()}, closed={session._closed}")
 
 
 async def _heartbeat_loop(websocket: WebSocket) -> None: