Function shutdown

src/main.tsx:4764–4772

()

          let shuttingDown = false;
          const shutdown = async () => {
            if (shuttingDown) return;
            shuttingDown = true;
            // Stop accepting new connections before tearing down sessions.
            server.stop(true);
            await sessionManager.destroyAll();
            await removeServerLock();
            process.exit(0);
          };
          process.once('SIGINT', () => void shutdown());
          process.once('SIGTERM', () => void shutdown());
        },