**A defect, not a coverage gap** — found while trying to pin
`agentParkedColumns` from the #3115 map.
`recoverDriftedAgentTaskLinks` enters its preservation branch on a
**resolved** question (`isPreWipColumn`) and then decided it on a
**literal** one: `evaluateParkedAgentTaskLink` was called without
`parkedColumns`, so parked-ness fell back to `todo`/`triage`. The
sibling sweep passes the resolved set; this call site did not.
On a renamed board: the card is pre-wip, `isParkedTaskColumn` says no,
`shouldPreserveParkedLink` is false, and **an agent with a fresh
heartbeat run has its task link cleared — while it is working.**
`task-agent-sync.ts` predicted this in writing when the parameter was
introduced:
> *"turning a stale-link bug into a dropped-link bug, since the card
would be treated as unparked and its live agent link cleared"*
That is what an unpassed optional lane parameter costs — the same
missed-pair shape as #2956, #2963 and #3186.
## The test needed two fixture corrections, both caught by failing
- the renamed IR had **no hold column**, so no card could be pre-wip at
all;
- the **per-task selection readers** were missing, so `isPreWipColumn`
resolved the default IR and the branch was never entered.
Either alone made the case pass while exercising nothing. Third time
today a fixture passed for a reason unrelated to the resolver — a
pattern, not an anecdote.
## Measured
15 pass; removing `parkedColumns` from the call fails exactly this case.
## Note on how it was found
I had discarded a probe at this sweep earlier for failing to
discriminate. Coming back with the obstacle understood — the fixture
must reach the branch the resolver gates — turned a coverage miss into a
defect find. The five discards this session were not wasted; three of
them named the obstacle that made a later attempt work.
## Verification
`self-healing-agent-link-drift` **15 passed** · `pnpm test:gate` 161 +
13 + 499 + 71 · lint · lane-wiring — green.
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