Task Queue - Wait for Current Task Completion Before Submitting New Instructions

[juneleung]

Is your feature request related to a problem? Please describe.

When submitting a new instruction while a previous task is still running, the new instruction interrupts the ongoing task midway. The two tasks then run in an interleaved/mixed manner, which can lead to:

• Incomplete execution: The first task may never finish properly.
• Unpredictable behavior: Outputs from both tasks get mixed together.
• Data corruption: Shared state or files may be left in an inconsistent state.

Example scenario:

1. User submits Task A (e.g., "Process all papers in collection X")
2. Task A is 50% complete
3. User submits Task B (e.g., "Export labels to JSON")
4. Task A is interrupted, Task B starts
5. Both tasks run interleaved, producing mixed/unexpected results

Describe the solution you'd like

Add a task queue mode option that ensures instructions are executed sequentially:

• Default mode (current behavior): New instructions can interrupt ongoing tasks (backward compatible).
• Queue mode (new option): When enabled, new instructions are queued and wait for the current task to complete before starting.

Suggested behavior when queue mode is enabled:

• Display: "Task already running. Your instruction has been queued."
• Execute tasks FIFO (First In, First Out)
• Show queue status: "X tasks in queue, currently executing: [task name]"
• Allow queue management: view queue, cancel queued tasks

Describe alternatives you've considered
None yet, wait for completion and then enter the next prompt.

Additional context