fix: cleanup_loop correctly frees and restarts RDP slots on session expiry

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/main.py

@@ -1634,16 +1634,25 @@ def cleanup_loop():
                 SessionModel.last_access_at < cutoff,
             )
             stale = db.scalars(q).all()
+            rdp_slots_to_restart: list[int] = []
             for sess in stale:
-                if sess.container_id and not (
-                    sess.container_id.startswith("POOL:")
-                    or sess.container_id.startswith("POOLIDX:")
-                    or sess.container_id.startswith("WEBPOOLIDX:")
+                cid = sess.container_id or ""
+                if cid.startswith("RDPSLOT:"):
+                    try:
+                        rdp_slots_to_restart.append(int(cid.split(":", 1)[1]))
+                    except Exception:
+                        pass
+                elif cid and not (
+                    cid.startswith("POOL:")
+                    or cid.startswith("POOLIDX:")
+                    or cid.startswith("WEBPOOLIDX:")
                 ):
-                    stop_runtime_container(sess.container_id)
+                    stop_runtime_container(cid)
                 sess.status = SessionStatus.EXPIRED
             if stale:
                 db.commit()
+            for slot_id in rdp_slots_to_restart:
+                threading.Thread(target=_restart_rdp_slot_bg, args=(slot_id,), daemon=True).start()
         except Exception:
             db.rollback()
             logger.exception("cleanup_loop_failed")