fix(ci): harden Bun isolate worker teardown and probe timeouts

[Wibias]

Summary

• extend the storage Worker post-close OS-join settle to Linux, where Bun 1.3.14 is also showing isolate/reclaim failures
• keep the longer 1.5s Windows settle while using a 250ms reclaim window on Linux/macOS
• add a regression test that pins the per-platform settle policy
• bound the synchronous Claude launcher-context probe with a 3s timeout and hard kill so a wedged child cannot consume the entire CI job

Failure observed

Linux shard test 3/4 repeatedly fails under Bun 1.3.14 with two linked symptoms:

1. tests/api-storage-policy-already-running.test.ts hits an unhandled Bun runtime failure while creating a stream around Worker activity:

error: EEXIST: file already exists, epoll_ctl
at new WriteStream (internal:fs/streams:244:58)

Bun then reports test-runner corruption (Cannot call beforeEach() after the test run has completed) but continues into later files.

2. Once the corrupted shard reaches tests/claude-dotenv-provenance-transport.test.ts, its unbounded spawnSync() child can wedge. The log shows killed 1 dangling process, followed by no progress until the 15-minute job timeout.

The repository already documents Bun 1.3.14 Worker-reclaim crashes on Ubuntu, but worker-lifecycle.ts only applied its post-close OS-join settle on Windows/macOS. This PR closes that Linux gap and independently makes the Claude subprocess fail boundedly instead of hanging the whole shard.

Test coverage

• new pure regression test covers Windows/macOS/Linux settle values
• existing Claude transport tests continue exercising the real child-process path, now with a bounded subprocess lifetime
• full cross-platform CI should verify whether the repeated Linux test 3/4 hang is eliminated

Scope

This is intentionally separate from #1175; it changes only CI/runtime hardening for the pre-existing Bun isolate failure and subprocess hang.

Summary by CodeRabbit

• Bug Fixes

  • Improved worker shutdown timing across Windows, macOS, Linux, and other platforms.
  • Added support for Linux and Bun 1.3.14 behavior during worker termination.

• Tests

  • Added coverage for platform-specific shutdown delays.
  • Improved child-process test reliability with probe timeouts and explicit termination handling.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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Run ID: b131c510-f364-4638-8891-00e616ea91c8

📥 Commits

Reviewing files that changed from the base of the PR and between 6d04574 and a53163f.

📒 Files selected for processing (3)

• src/storage/worker-lifecycle.ts
• tests/claude-dotenv-provenance-transport.test.ts
• tests/storage-worker-os-join-settle.test.ts

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📝 Walkthrough

Walkthrough

The worker lifecycle now exports platform-specific OS-join settle durations and applies them during termination. Tests cover Windows, macOS, Linux, and FreeBSD. A child-process probe test now has bounded execution and explicit spawn-error handling.

Changes

Worker OS-join settling

Layer / File(s)	Summary
Platform settle policy and termination integration src/storage/worker-lifecycle.ts	The lifecycle exports storageWorkerOsJoinSettleMs, returning 1,500 ms for Windows, 250 ms for Darwin and Linux, and 0 ms otherwise. Termination preserves the zero-delay yield and sleeps only when the selected duration is positive. Documentation records the supported platform cases.
Platform coverage and probe cleanup tests/storage-worker-os-join-settle.test.ts, tests/claude-dotenv-provenance-transport.test.ts	Tests verify settle durations for Windows, macOS, Linux, and FreeBSD. The child-process probe uses UTF-8 output, an explicit environment, a 3-second timeout, SIGKILL, and immediate spawn-error propagation.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• lidge-jun/opencodex#827: Both changes modify worker lifecycle OS-join settle delays.
• lidge-jun/opencodex#849: Both changes adjust platform-specific worker OS-join settling.

Suggested labels: bug

Suggested reviewers: ingwannu, lidge-jun

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main changes: hardened Bun worker teardown and bounded probe timeouts.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/bun-isolate-worker-hangs

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Give the Bun child a contention-safe deadline

On contended cross-platform runners, this 3-second ceiling can turn a healthy cold Bun launch into ETIMEDOUT, and line 46 then fails all three transport tests before they exercise the behavior. The Windows CI notes in tests/codex-catalog-restore.test.ts:41-42 record the same spawnSync(bun ...) pattern taking about 5.4 seconds under load, while tests/helpers/test-budget.ts:33-34 assigns real child processes a 45-second budget. Keep the subprocess bounded, but use a deadline with CI-contention headroom (and an appropriate outer test budget) rather than 3 seconds.

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[github-actions]

✅ Deterministic PR hygiene checks passed.