`recoverForeignOnlyContaminatedInReviewTasks` classifies a branch
carrying **only foreign commits** and clears the contamination park that
nothing else clears. Two literal reads meant that on a renamed board it
classified nothing, and the task stayed parked indefinitely.
## The two redundant guards were the interesting part
Both filters carried a `task.column === …` check that was **redundant**
while the query pinned the column. Under a resolved read they stop being
redundant and become the per-card verdict — so they convert here rather
than being deleted. Deleting them would have silently widened the sweep,
which is the failure this whole class is about.
## Dedupe matters more here than elsewhere
The concatenated candidate list is deduped (the P1 reviewed on #2879).
It bites harder in this sweep because the two filters have **different
predicates**: a column carrying both a review role and the wip role
could satisfy both and classify one branch twice.
Explicit `has` guard rather than `new Map(entries)` — that constructor
keeps first insertion *order* but the **last** value for a repeated key,
so it reads as first-bucket precedence while doing the opposite.
(Corrected in #2879 and #2883 for the same reason.)
## Revert results
Each applied alone and the file re-run:
| conversion | reverted → |
| --- | --- |
| the resolved reads | fails — the card is never listed, so the
classifier is never called |
| the review verdict | fails — the renamed review lane does not match
and the card is filtered out |
Observable is **candidacy**: `classifyForeignOnlyContamination` runs
once per accepted card and not at all for a rejected one, which is
exactly the read-plus-verdict under test. It is a static named import,
so it is intercepted with a scoped `vi.mock` (spyOn cannot rebind an
already-resolved ESM binding); only that one export is overridden, so
the sweeps in this file that use `inspectBranchConflict` are unaffected.
A non-vacuous companion (same card in the board's hold lane → never
classified) rules out a read that returns everything.
## Verification
`pnpm test:gate` 161 + 487 + 13 + 71, plus `self-healing.test.ts` 412;
`tsc` engine clean; `pnpm lint`, `check:changesets`, census `--strict`
clean, each run explicitly.
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
c6767cb258