fix(laws): read the hook executable bit from the git index

[ruleofcodedev]

Closes #15. Reported independently by a Windows consumer who stayed on 7.17.4 because this blocks their build.

The false positive

Git Hook Compliance called every hook of every Windows project non-executable — and the consumer could not act on it. Measured, not assumed:

fs.statSync('.husky/_/pre-commit').mode & 0o777   // 666
fs.chmodSync('.husky/_/pre-commit', 0o755)
fs.statSync('.husky/_/pre-commit').mode & 0o777   // 666  ← unchanged

NTFS has no POSIX execute bit, so chmod +x — the suggestion the law printed — changes nothing. It also judged files git never runs: husky keeps .gitignore, husky.sh and h in its hooks directory.

The true positive, kept

The law was right about the defect underneath: hooks committed at 100644 are not executable when the repo is cloned on Linux. Keeping that was the harder half.

The committed layout is .husky/<hook>, not the resolved hooks directory (.git/hooks, or husky's untracked _). Reading only the resolved directory would have removed the false positive and the true one — my first version scored 100/100 against hooks that were genuinely 100644. The check now reads both.

Our own hooks were committed at 100644. Fixed in this PR — the law was right about us.

Evidence

Proven red and green on this repository:

100644                        → • Hooks committed without the executable bit: commit-msg, pre-commit, pre-push
git update-index --chmod=+x   → Git Hook Compliance (Score: 100/100)

Plus five regression tests on a real git fixture with committed hooks and an untracked husky _ directory.

Verdict impact

Changes verdicts: the unactionable Windows violation disappears; committed-but-non-executable hooks are still reported, with an actionable message (git update-index --chmod=+x). Three new detectionLimits entries declare what is now not checked — untracked hooks carry no mode to judge.

Gate

• npm run lint — 0 errors
• npx jest — 505 suites / 13871 tests, exit 0
• npm run canary — green (py100 / ng136 / node78)
• node dist/cli.js audit — exit 0