Follow-up to the budget-exhaustion recovery fix. recompute_ready's
new circuit-breaker guard resolved its effective limit from per-task
max_retries -> DEFAULT_FAILURE_LIMIT, skipping the dispatcher's
configured kanban.failure_limit. _record_task_failure resolves
max_retries -> failure_limit(config) -> DEFAULT, so the two disagreed
whenever an operator set kanban.failure_limit != 2:
- config > 2: a task could get stuck at DEFAULT(2) before reaching its
allowed retry count.
- config < 2: a task the breaker already blocked could be auto-recovered
back to ready, defeating the stricter limit.
Thread the dispatcher's failure_limit through dispatch_once into
recompute_ready so the guard and the breaker share one resolution order.
Updated test_circuit_breaker_block_still_auto_promotes (it asserted a
failures=5 block auto-recovers and resets the counter — that's the
pre-#35072 behavior the loop fix removes); it now exercises a below-limit
transient block, with the at-limit case covered in test_kanban_db.py.
Added two tests for the config-tier and per-task override resolution.
Six regression tests pinning the dispatcher contract that was broken
in #28712:
* test_worker_block_is_not_auto_promoted_by_recompute_ready —
kanban_block survives five back-to-back ticks (compressed dispatcher
loop).
* test_worker_block_on_child_with_done_parents_is_still_sticky —
the parent-completion code path was the worst false-positive; even
when every parent is done, an explicit worker block stays blocked.
* test_circuit_breaker_block_still_auto_promotes — preserves the
pre-#28712 recovery semantics for circuit-breaker blocks (direct
UPDATE + no "blocked" event).
* test_gave_up_event_alone_does_not_make_block_sticky — explicit
guard so the gave_up event is never accidentally treated as
sticky; covers the second leg of the protocol_violation loop.
* test_unblock_clears_sticky_state_and_lets_block_recover — only
unblock_task resolves the sticky state; subsequent circuit-breaker
blocks recover normally.
* test_protocol_violation_loop_is_broken — full bug-shaped
reproduction: block → tick → (would-be) crash + gave_up → next tick
still blocked. Without the fix this would loop indefinitely.
The seventh test from the original PR (legacy-DB init recovery) was
dropped during salvage — the schema-init half of #28712 is already
fixed on main by #28754 and #28781, and the contract is covered by
test_kanban_db.py::test_connect_migrates_legacy_db_before_optional_column_indexes.
