fix: recycle webpool container on TERMINATED sessions too

terminate_session_record was explicitly skipping WEBPOOLIDX containers.
Now stops portal-webpool-N in a background thread on any session close,
so ensure_web_pool recreates it fresh for the next user.

app/runtime.py

@@ -745,8 +745,15 @@ def terminate_session_record(
         return
     old_status = sess.status
     cid = sess.container_id or ""
-    if stop_container and cid and not cid.startswith(("POOL:", "POOLIDX:", "WEBPOOLIDX:", "RDPSLOT:")):
-        stop_runtime_container(cid)
+    if stop_container and cid:
+        if cid.startswith("WEBPOOLIDX:"):
+            try:
+                slot = int(cid.split(":", 1)[1])
+                threading.Thread(target=stop_runtime_container, args=(web_pool_container_name(slot),), daemon=True).start()
+            except Exception:
+                logger.exception("webpool_slot_recycle_failed cid=%s", cid)
+        elif not cid.startswith(("POOL:", "POOLIDX:", "RDPSLOT:")):
+            stop_runtime_container(cid)
     if cid.startswith("RDPSLOT:"):
         try:
             slot_id = int(cid.split(":", 1)[1])