Deflake early-hints integration deployment on Windows

[kriszyp]

The Windows early-hints failure never reached /hints: the archived server log shows deploy_component entered npm install at 07:18:51 and produced no further output before undici's 300-second headers timeout. The Operations API holds response headers until deployment completes, so the accepted connection was waiting on the stalled child process, not an HTTP startup/readiness race; I could not reproduce or recover the deeper npm-internal cause from the one failed run.

This keeps the behavior fixture hermetic by replacing its unused source-toolchain install with node --version, then bounds every suite request with diagnostics that name the request and URL. Refs Windows Integration Testing #525; this is not the readiness/loopback race tracked by Integration test harness: startup-deadline and teardown/loopback-recycle races #1139.

For the human reviewer

1. Bypass the fixture install: The packaged runtime imports only Harper and local files, so this endpoint suite skips the package's source-only development toolchain. Keeping the normal install would preserve packaging coverage but retain the observed external npm hang; this choice is easy to reverse.
2. Keep the timeout helper local: The failing request is suite-specific and the shared @harperfast/integration-testing package cannot abort sendOperation, so this test posts deployment directly through a local helper. Extending the shared package would improve consistency but widen this deflake into a separate repository/API change.
3. Use fixed timeout budgets: Ordinary requests abort after 10 seconds and deployment after 30 seconds. With installation reduced to a no-op, exceeding these limits indicates a stalled or severely degraded local deployment; the values remain easy to tune if Windows CI proves them too tight.

Verification

• End-to-end route: extended the existing Component: early-hints integration suite; Linux passed all 12 tests three times against freshly built dist (7.6s, 7.7s, and 7.8s).
• npm run build — passed.
• npm run lint:required — passed.
• PR CI — the relevant integration shard 3 passed on Windows Node.js 24 (6m36s) and Linux Node.js 24 (4m15s); unit matrices passed on Node.js 22, 24, and 26.
• The one-night npm hang did not reproduce locally; the root-cause trace comes from the archived failed-run server log.

Complexity: easy

🤖 Generated by GPT-5 Codex.

_{Review-Coverage: authored=codex; ran=gemini; adjudicated=domain; declined=claude,cursor-grok,cursor-composer; rounds=2 @ e113c4c}

_{Human-Review-Need: 3 (decisions: local-timeout-wrapper, bypass-fixture-install, per-request-timeout) @ e113c4c}

[gemini-code-assist]

Code Review

This pull request introduces a fetchWithTimeout helper function in the early-hints integration tests to replace standard fetch calls, preventing tests from hanging indefinitely. It also refactors the component deployment step to use this helper with a custom timeout and payload. The feedback suggests improving error diagnostics during deployment by reading the response as text before parsing it as JSON, which prevents a SyntaxError from masking the actual HTTP status code if the deployment fails with a non-JSON response.

[claude]

Reviewed; no blockers found. The prior non-blocking suggestion (JSON parse ordering on deploy response diagnostics) has been addressed in e113c4c.