Claimed `auto-merge-finalization.ts` — and this one is a **reversal of
an earlier audit in the same file**, which is the interesting part.
## The earlier note said "diagnostic only". It was wrong about the
consequence
`validateWorkflowDoneMergeProof` picks between two refusal reasons with
`task.column === "done"`. Both arms return `{ ok: false }`, so this
never changed which branch ran — and on that basis a prior pass recorded
it as *"REAL but DIAGNOSTIC-ONLY"* and declined it, reasoning that
widening a signature to improve an error string is a poor trade.
**The reason is not an error string.** It is written to run-audit
metadata alongside `previousColumn` — `merger-merge-lifecycle.test.ts`
asserts exactly that — and that row is what an operator reads to find
out why a merge was refused.
So on a board whose complete lane is not called `done`, a card resting
in that lane was refused with the generic `missing-merge-confirmation`:
the classification for a card that is **not in the complete lane at
all**. The audit trail recorded the opposite of what happened. A wrong
record is worse than a vague one, because it gets acted on.
## The trade was also cheaper than the note claimed
The function is **already async** and **already takes an options bag**.
`resolveFinalizationColumns`, two functions up in the same file,
**already builds this exact predicate** for its own guard.
Nothing new is resolved. The answer that existed is handed down instead
of being re-asked with an id — the half-conversion shape this program
keeps finding, here inside a single file, one line apart: the caller
guards on the resolved `isCompleteColumn(latest.column)`, then calls a
validator that re-asked the same question with the literal.
`isCompleteColumn` is **optional with the legacy literal as its
default** — the same default-to-legacy contract the lane-parameter
vocabulary uses elsewhere — and `check-lane-wiring` watches the
parameter, so the two call sites cannot silently stop passing it.
## Measured
- New `merge-proof-reason-renamed-complete-lane.test.ts` — **2 pass**.
- **MUTATION**: dropping the parameter fails the renamed case and leaves
the legacy **control** green. The control earns its place: a failure now
means *"renamed board"*, not *"the refusal stopped working"*.
- **Driven through `finalizeProvenAutoMergeTask`**, not by calling the
validator with the new argument. The contract under test is the
**wiring** — a test that passed the argument directly would assert my
own parameter works and prove nothing about the seam that was broken.
- **The audit row is asserted, not just the return value.** The return
value alone is not the contract that failed here.
- merger / auto-merge suites — **5 files / 159 tests pass**.
- `tsc --noEmit -p packages/engine` clean; census `--strict`,
`check-lane-wiring`, `check-inert-sync-lane-conversions`,
`check-fnxc-future-dates` clean.
## Census
`auto-merge-finalization.ts` stays at **2**, deliberately. Both
remaining entries are now documented **degraded-fallback arms** — the
resolver's `catch` and this parameter's default — which is the right
kind of literal rather than a missed conversion. Converting a fallback
to a resolution would defeat its purpose.
## A note on the FNXC gate
My first stamps were dated `2026-08-01` while local today is
`2026-07-31`. `check-fnxc-future-dates` caught it and I re-stamped.
Worth mentioning because it is the second time this session that a
date-only local-calendar comparison has caught a stamp written near
midnight — the gate is doing real work, not ceremony.
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>