Method setCatchUpGate

src/mcp/tools.ts:877–879

* Engine-only: register the catch-up sync promise so the next `execute()` * call awaits it before serving. The handler swallows rejections (the * engine logs them) so a sync failure never propagates as a tool error; * we still want to serve a best-effort result over the same potentially-

(p: Promise<void> | null)

   * stale data, which is what would have happened without the gate.
   */
  setCatchUpGate(p: Promise<void> | null): void {
    this.catchUpGate = p;
  }

  /**
   * Await the catch-up gate, but no longer than the configured timeout (#905).