The last fan-out guard, and the one I explicitly said needed a
synchronous answer. #3109 made that answer available without an await,
so the flag comes off.
## Why this one was last
The other two guards in this listener gated work the listener **already
`void`s**, so they moved onto the async resolver in #3094. This one
increments in-memory state **in the handler's own tick**, so it
genuinely needed a synchronous answer.
The sync IR path was never that answer: `resolveTaskWorkflowIrSync`
cannot resolve a **custom** workflow at all — two independent blockers,
#3103 — which is why I wrote that conversion, measured it, and withdrew
it.
#3109's emitter-carried `lanes` removes the dilemma rather than trading
one horn for the other: reading them needs **no await**, so the
increment stays in the same tick *and* the guard becomes correct.
## What it fixes
On a renamed board this counter read **zero**. The board-stall watchdog
was blind to a board whose cards were moving out of implementation the
whole time — the signal it exists to raise was never raised.
## Census
| | before | after |
|---|---|---|
| `self-healing.ts` | 6 | **1** |
| repo backlog | 29 | **24** |
The remaining 1 is the log-dedup closure — a pre-existing flag whose
degraded answer costs a duplicate log line, not a lifecycle decision.
## Measured
- 3 new cases; `self-healing-completion-fanout.test.ts` **13/13 pass**.
- **MUTATION**: restoring the literal pair fails the renamed case.
- **The paired negative is the load-bearing one.** The guard means
*"left implementation for somewhere that is not implementation"*, so a
move **between two non-wip lanes** must not count. Without that case, a
conversion that counted every move would pass the positive and inflate
the watchdog's denominator — breaking it in the opposite direction,
which is harder to notice than a zero.
- A **fail-soft** case pins that an emit carrying no `lanes` still
counts on the legacy ids.
- **Asserted through the counter itself**, not a downstream alert. The
increment *is* what this guard decides; routing the assertion through
the watchdog would let an unrelated threshold change mask a regression
here.
- `src/__tests__/self-healing*` + `task-agent*` — **42 files / 848 tests
pass**.
- `tsc --noEmit -p packages/engine` clean; census `--strict`,
`check-lane-wiring`, `check-inert-sync-lane-conversions`,
`check-fnxc-future-dates` clean.
## On the withdrawal this reverses
#3094 withdrew a sync-IR conversion of this listener and recorded why,
precisely. That record is what made this cheap: I could tell in one read
that #3109 addressed the *specific* obstacle rather than a general
"async is hard". A flag that names its blocker exactly is a flag that
can be retired the day the blocker goes.
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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