fix(kanban): make creation-time blocks sticky

[aslxiaomu]

中文摘要

• create_task(initial_status="blocked")现在在同一 SQLite 事务写入created和初始blocked事件。
• recompute_ready不再把创建即阻断的任务提升为ready。
• block_task允许给尚未运行且已 blocked 的任务追加持久原因事件，不伪造 run，也不重复增加循环次数。
• 显式unblock_task仍是唯一解除路径。

Summary

Make creation-time blocked tasks sticky by persisting the initial block event atomically. Allow an already-blocked, never-run task to receive a durable reason annotation without fabricating a run or inflating recurrence counters.

Verification

• tests/hermes_cli/test_kanban_blocked_sticky.py: 10 passed
• affected matrix: 645 passed, 1 skipped, plus one pre-existing order-dependent WAL warning test failure; the same failure reproduces on origin/main and passes in isolation
• ruff check: passed
• full-suite attempt is not claimed green: local E2E logging teardown races produced pre-existing failures and timed out at 600s

[teknium1]

Thanks for identifying a real create-time state gap: current create_task emits only created for initial_status="blocked" (hermes_cli/kanban_db.py:3172-3191), while recompute_ready only preserves a blocked row when _has_sticky_block() finds a blocked event (hermes_cli/kanban_db.py:3950-4035).

Problems

• The new annotation branch matches any status == "blocked" row, not specifically a creation-time hold (hermes_cli/kanban_db.py:5450 in this PR). Circuit-breaker blocks are intentionally recorded as gave_up and remain auto-recoverable (hermes_cli/kanban_db.py:3962-3977, 7641-7766); this branch would append blocked and make them sticky.

Suggested changes

• Retain the atomic create-time event, but constrain/remove the annotation path so it cannot alter circuit-breaker recovery semantics.
• Add a regression for an auto-blocked gave_up row.
• Please consolidate the overlapping create-time repair with #71147, as noted in its maintainer comment.

Automated hermes-sweeper review.

[teknium1]

This condition identifies every blocked row, not just one created with initial_status="blocked". Circuit-breaker rows are intentionally blocked with a gave_up event and should remain auto-recoverable; appending blocked here makes _has_sticky_block() suppress that recovery. Please require a durable creation-time marker or remove this annotation path.