Show submission queue status

[msaroufim]

Summary

Displays KernelBot submission queue metadata in the CLI when the API provides it.

The CLI parses the optional aggregate queue object, prints queue position/counts in --no-tui polling logs, and forwards the same live status text into the TUI loading screen. Older API responses without queue remain supported.

Why

Submitters get clearer feedback about whether a job is waiting in KernelBot's local queue or has moved into runner execution, without exposing who else is in the queue.

Validation

• cargo test

[msaroufim]

Additional local e2e validation after opening the PR:

• Ran a local FastAPI KernelBot harness on 127.0.0.1:8766 using the real BackgroundSubmissionManager and a fake runner/DB.
• Preloaded one pending job, held workers at 0, submitted a second job through the actual popcorn-cli binary over HTTP, then released workers.
• CLI output included:

Submission 1001 accepted (kernelbot queue position 2, 1 ahead; 2 pending, 0 running, workers 0/0; runner queue not visible). Waiting for results...
Submission 1001 status: pending (kernelbot queue position 2, 1 ahead; 2 pending, 0 running, workers 0/0; runner queue not visible, 0s)
Submission 1001 status: pending (kernelbot queue position 2, 1 ahead; 2 pending, 0 running, workers 0/0; runner queue not visible, 5s)
Submission 1001 status: succeeded (kernelbot queue: 0 pending, 0 running, workers 2/2; runner queue not visible, 10s)

This verifies the API response shape and CLI display path end to end without invoking Modal/GitHub.

[msaroufim]

Updated after simplifying the queue status shape.

Local e2e validation with a real HTTP path still passes:

• Ran a local FastAPI KernelBot harness on 127.0.0.1:8766 using the real BackgroundSubmissionManager and a fake runner/DB.
• Preloaded one pending job, held workers at 0, submitted a second job through the actual popcorn-cli binary over HTTP, then released workers.
• CLI output now uses the simplified messages:

Submission 1001 accepted: In KernelBot queue (position 2, 1 ahead). Waiting for results...
Submission 1001 status: pending - In KernelBot queue (position 2, 1 ahead) (0s)
Submission 1001 status: succeeded - Job dispatched to Modal/GitHub runner (5s)

The public queue payload is now limited to stage, message, and optional position / jobs_ahead.

[msaroufim]

Closing this draft; the paired KernelBot queue-position API is not the right direction for debugging submission wait time.