Manage and close bot tasks from /bot without losing work

[d3cker]

The /bot picker previously only opened sessions, so an obsolete or broken task remained in the blocked counter even after its GitHub issue/PR disappeared. Add a per-task action menu: open the session, inspect saved details, close idle tabs, restart a workflow, or stop sessions and end tracking.

Confirmed closure is durable: save closing before interrupting all known task sessions, wait for idleness and in-flight worker/question operations, then save closed. Preserve files, branches, worktrees, session history and pending feedback. Closed records prevent rediscovery and cannot be revived by late checkpoints, new comments or workflow recovery. Missing sessions do not prevent closure; interruption failures remain visible and retry after 30 seconds or from the menu. There are no GitHub issue/PR close or delete calls.

Closing an already-started publication/merge is rejected with an actionable message. Other in-flight local operations may finish, but cannot advance to publication. Pending closure holds new worker passes; unrelated work already running can finish. Runtime question/helper admission stops once closure is requested.

The sidebar now names attention tasks and their saved errors, reports pending closures separately, and excludes locally closed tasks from live counts. Closing idle tabs remains a separate local UI action that does not stop task tracking.

Validation:

• npm run check: lint, types, 175 tests, native TUI render tests and build passed.
• Regressions cover missing GitHub objects, active-session interruption, late checkpoints/prompts, failed closure recovery after restart, preserved questions/history, publication races, closure during verification, related/missing sessions, menu confirmation, and sidebar counts.
• npm run package:check: isolated installation, loaders, SDK entrypoints and CLI passed.
• All eight updated workflow diagrams parsed; 75 local documentation links and diff formatting passed.

Documentation updated: README, runtime actions and limits, architecture, advanced RPC/persistence, installation/reopen guidance, all affected workflow diagrams, AGENTS map and Unreleased notes. Older plugin builds do not understand the new queue statuses, so retain backups before any downgrade.

Targets devel. No release, server deployment, or live task closure is included in this PR.