fix(#667): circuit breaker — mark task BLOCKED after N consecutive silent recoveries (#707)

* chore: gitignore personal kaia/council skills; untrack kaia SKILL.md

* fix(#667): circuit breaker — BLOCK task after N consecutive silent recoveries

Fix 3a from issue #667 (the board-policy half; the spawn-backoff half
3b is intentionally NOT built — the spawn controller is deleted by the
session-model migration, epic #706).

A "silent" recovery is a lease recovery where the agent never reported
progress (renewal_count == 0, the `updates=0` signature of the
snake_game runaway: 81 registrations over 3+ hours). After
max_silent_recoveries (default 3) consecutive silent recoveries,
recover_expired_lease now marks the task BLOCKED instead of returning
it to TODO: BLOCKED tasks are never offered by request_next_task, so
the reclaim/re-assign loop physically cannot continue — regardless of
who supplies agents (Invariant #1: the guard lives in Marcus, not the
spawner).

- A recovery WITH progress resets the streak (slow-but-alive is not
  the silent-failure pattern — the #703 lesson at board level)
- BLOCKED path performs the same coordination cleanup as normal
  recovery (lease, persistence, server callback) — no #485-class leaks
- Diagnostic kanban comment + task_blocked_circuit_breaker history
  event; human resets to TODO to retry (streak starts fresh)

8 new tests; full lease module 74/74; mypy + pre-commit clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(#667): persist BLOCKED via move_task_to_column for external providers

Codex P2 on PR #707: GitHub- and Linear-backed boards don't persist
status through update_task (GitHub only opens/closes the issue; Linear
ignores status) — their blocked-state mechanics live in
move_task_to_column. The breaker now also calls
move_task_to_column(task_id, 'blocked') (GitHub 'blocked' label /
Linear 'Blocked' state / SQLite direct status match) so a project
refresh can't resurrect the task as TODO and resume the loop.

+2 tests: move called with 'blocked' on trip; client lacking the
method degrades gracefully (update_task path still lands).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lwgray

.gitignore

@@ -57,3 +57,7 @@ package-lock.json
 # can leak into the repo root; ignore at root to prevent accidental commits.
 AGENTS.md
 experiment_complete.json
+
+# Personal advisory tooling — keep out of the public Marcus repo
+skills/kaia/
+skills/council/