test(vscode): harden startup-deadline E2E test against slow runners

[fi3ework]

Summary

• Widen the never-settling startup-operation deadline from 50ms to 500ms so slow CI runners can invoke the operation before the deadline.
• Match only the in-flight timeout message, preventing an already-expired deadline from satisfying the assertion.
• Document the targeted divergence from the upstream-ported test inline and in the VS Code extension agent guidance.

Root cause

On a stalled Windows runner, more than 50ms could elapse between constructing the absolute deadline and runBeforeDeadline recomputing the remaining time. The helper then rejected through its already-expired path without invoking the operation. The previous regex accepted both timeout paths, so the test failed later at the attempts === 1 assertion instead of identifying the wrong rejection path.

Verification

• pnpm lint && pnpm test:unit — passed (165 linted files; 31 test files and 264 tests passed)
• VSCODE_CLI=1 pnpm test:e2e lint — passed (15/15 lint E2E suite launches exited successfully)

Related Links

• chore(deps): update rstack toolchain #47

Checklist

• Tests updated.
• Documentation updated.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-04T03:27:37.230410Z	5082da3	PR opened

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