Method startGrace

src/server/web/session-store.ts:96–120

* Detach the WebSocket from a session and start the grace period timer. * After `gracePeriodMs` with no reconnect, `onExpire` is called and the * session is destroyed.

(token: string, onExpire: () => void)

   * session is destroyed.
   */
  startGrace(token: string, onExpire: () => void): void {
    const session = this.sessions.get(token);
    if (!session) return;

    session.ws = null;
    session.lastActive = new Date();

    if (session.graceTimer) {
      clearTimeout(session.graceTimer);
    }

    const remainingSec = Math.round(this.gracePeriodMs / 1000);
    console.log(
      `[session ${token.slice(0, 8)}] Disconnected — grace period: ${remainingSec}s`,
    );

    session.graceTimer = setTimeout(() => {
      session.graceTimer = null;
      console.log(
        `[session ${token.slice(0, 8)}] Grace period expired — cleaning up`,
      );
      this.destroy(token);
      onExpire();
    }, this.gracePeriodMs);
  }

  /**
   * Immediately kill the PTY and remove the session.