test: a skill-sync test passes without the memo clear it is named for #1466

What

packages/opencode/test/altimate/workspace/skill-sync.test.ts › "linking just after an unbound turn is not undone by the negative cache" passes whether or not recordApprovedBinding calls clearLookupMiss (src/altimate/workspace/state.ts).

The link also stamps the row as validated. Inside the revalidation window a validated row is trusted without a lookup, so the memoized miss is never read. The test therefore pins "the link counts as validated", not "the link clears the miss memo". (Raised in the review of #1399.)

Reproduce

Comment out clearLookupMiss(directory, key) in recordApprovedBinding and run the test: it still passes.

Suggested fix

A second test that expires the validation stamp after linking (expireValidationForTests), so the next sync has to look the binding up, and asserts that the lookup happens and the row survives.