[WRONG BRANCH] fix(lab): retain grace period for stale ledger locks

[luvs01]

Motivation

• A recent change made stale-lock recovery treat any lock whose recorded PID is dead as immediately recoverable, which exposed an ABA race allowing a waiter to unlink a newly created live lock and violate ledger serialization.
• The intent is to avoid deleting a live replacement lock installed between liveness check and unlink, restoring the previous freshness guard that reduced the recovery window for short-lived writers.

Description

• Change isLedgerLockStale in src/lab/ledger/store.ts to require that a well-formed lock is both owned by a dead PID and that its createdAt is older than LEDGER_LOCK_STALE_MS before it is considered stale.
• Keep the existing recovery mutex / recoverStaleLedgerLock path intact so stale recovery remains ownership-safe while refusing to reclaim freshly-created locks.
• Update the focused test in tests/lab-ledger-mutation-lock.test.ts to set the lock createdAt to older than LEDGER_LOCK_STALE_MS and rename the test to reflect the aged-lock expectation.
• Commit message: fix(lab): retain grace period for stale ledger locks.

Testing

• Ran bun run typecheck with no errors.
• Ran the focused test file with bun run test -- tests/lab-ledger-mutation-lock.test.ts and observed all tests in that file pass (5 passed).
• Verified git diff --check and committed the changes locally as described; a full repository test run in this environment was started but large unrelated suites produce long output and were truncated, so only the focused tests were used for verification.

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📥 Commits

Reviewing files that changed from the base of the PR and between d9de895 and 9a0fd13.

📒 Files selected for processing (2)

• src/lab/ledger/store.ts
• tests/lab-ledger-mutation-lock.test.ts

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✅ Deterministic PR hygiene checks passed.

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Recover recently orphaned locks without waiting a minute

When a ledger owner crashes or is killed less than 60 seconds after acquiring the lock, this new age condition treats its lock as live even though the PID check would prove the owner is gone. tryAcquireLedgerLock only waits 5 seconds (LEDGER_LOCK_WAIT_MS), so every Lab mutation during the remaining grace period synchronously blocks for five seconds and then fails with EEXIST, preventing experiment results and other ledger updates from being persisted after a normal crash/restart. Preserve the ABA protection by making recovery conditional on the identity of the lock that was inspected, rather than delaying recovery of every dead owner beyond the acquisition deadline.

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