Named queue batches and in-app release notes

Queue work as named batches, stop and steer an interview mid-thought, and let a new version announce itself with release notes in the app.

Added

Name a group of queued tickets and start it as one batch that stops when it finishes
Interviews gain a Stop button, and you can type while the agent is still thinking
New versions announce themselves with a toast, a sidebar badge and a What’s new recap after upgrading
A quarantined ticket can be requeued from the web UI
Slices get their own CI gate, with a bounded repair loop working red checks before merge