fix(ops): merge-when-green commitlint check times out on the main checkout #1564

Found by the PO on 2026-11-01 while merging PR #1563.

Problem

lintHeader in scripts/ops/merge-when-green.mjs runs node_modules/@commitlint/cli/cli.js with a 60 s timeout (LINT_TIMEOUT_MS). On the Windows main checkout the same CLI run on a valid header takes about 110 s of wall time with almost no CPU (user 0.08 s), so the check fails closed with "commitlint could not run or timed out" and every merge stops. The header itself passes (exit 0). PR #1563 was merged with gh pr merge --squash --match-head-commit after a manual commitlint pass.

Expected

• Find what commitlint waits on (config loading of commitlint.config.ts, a network fetch, a file lock or antivirus scan) and remove the wait, or lint the header in-process with @commitlint/lint and the loaded config instead of spawning the CLI.
• A valid header lints in a few seconds on this machine; the fail-closed behaviour stays.
• Optional: an env override for the timeout.

Size: S