Live throttle control on the run console

[NitinKumar004]

What this adds

A live throttle slider on the run console. You can change a running operation's rate (rows/sec) at any time without stopping it — drag it down when production gets busy, drag it up when it's quiet. 0 means unthrottled.

Changes

• Backend — PATCH /runs/{id} now accepts {"action":"speed","rate":N}. It adjusts the running runner's token bucket immediately (solo mode) and persists the new rate on the task, so it survives a reload. A run.speed entry is written to the audit trail.
• Frontend — a Throttle slider on the run console, styled for both light and dark themes. The slider initializes from the task's current rate and debounces changes.
• Small helper: the dashboard now reads a ?theme= query param (used to capture the dark-mode screenshot below).

How to test

1. make up && make run, build the dashboard (cd web && npm run build), open http://localhost:8000/app.
2. Start a run, open it, and drag the Throttle slider — rows/sec responds live.
3. Reload the page: the rate you set is remembered. Check the audit trail for the run.speed event.

Screenshots

Captured with headless Chrome.

Run console — throttle slider (light)

Run console — throttle slider (dark)

Tasks — run history + open active run

Notes

• Live rate change applies in solo mode (in-process runner). In fleet mode the rate persists on the task and new leases pick it up; adjusting already-running fleet workers live is a follow-up.