[i098]

Closes #1091

Summary

Adds tools/ci-pool-tui, a read-only terminal view of the CI pool that flags held jobs and stuck slots. It installs as the ci-pool Herdr tab.

Screenshot: pending

What changed and why

• New TUI shows each ci-runner@ slot, GitHub runner state, queued and running workflow runs, and an optional Forgejo runs panel. Before this, an operator had to run systemctl, docker and gh by hand.
• Jobs queued over 5 minutes are flagged with a cause. A slot problem must last 2 minutes before it shows as stuck.
• GitHub reads stay at 20 calls a minute or fewer and pause until reset on a rate-limit error. It never restarts or cancels anything.
• Wired in as crewship.herdr.ci_pool_tab (default on): base.yml, default.yml, schema, docs/configuration.md, one pane test update, and a changelog fragment.
• The Forgejo panel is not tested against a live Forgejo, because no base URL is set on this host.

Test evidence

• bun test in tools/ci-pool-tui: 8 pass, 0 fail.
• uv run pytest tests/test_chart.py -k test_default_schedules_tab_preserves_existing_layout: passed.
• uv run ruff check: All checks passed.
• sentrux gate: no degradation detected.
• Live run against the real pool: 51 slots, 8 held jobs (all matching runners busy), one stuck slot that cleared on its own.
• no-mistakes run: review, test, document, lint and push passed.

Checklist

• One concern in this PR.
• The title uses the commit format, for example fix(provisions): check the digest before install.
• Tests pass (uv run pytest). Not applicable: the full suite timed out locally at 5 minutes; I ran the tests listed above only.
• Lint clean (uv run ruff check).
• Ansible syntax clean (--syntax-check). Not applicable: the change adds one list entry to base.yml and no task, and I did not run --syntax-check.
• Idempotent: launch → launch = changed=0 on the second run. Not applicable: no launch run; the new install task reuses the existing loop over crewship_tuis.
• A changelog fragment, changelog.d/<issue>.<type>.md (not a CHANGELOG.md edit), or the no changelog label.