Keep Untracked Files Out of the Pre-Commit Snippet's Prose Gate #3370

The prose-gate entry in catalog/snippets/pre-commit/.pre-commit-config.yaml runs the gate over . with --diff HEAD. pre-commit sets aside unstaged changes to tracked files before running a hook, but it leaves untracked files in place, and the gate's discovery includes them. So an untracked file holding a violation fails a commit that does not include it.

Reproduce in any repository carrying the snippet, with the hook config committed:

printf '# Scratch\n\nThis line has a semicolon; it should trip the gate.\n' > untracked-bad.md
printf '# Clean\n\nA clean line.\n' > staged-clean.md
git add staged-clean.md
pre-commit run

The prose gate fails on untracked-bad.md:3: semicolon, a file the commit does not carry. This was reproduced on ptr727/ESPHome-NonRoot#349, raised there by CodeRabbit.

GOVERNANCE.md "Running the Linters Locally" says the pre-commit scope "is the staged state instead", which is true for tracked files and not for untracked ones.

A likely fix: drop pass_filenames: false from the entry so pre-commit passes the staged paths, and take . out of the entry so those paths are the gate's paths argument, keeping --diff HEAD. Check that the gate still finds a violation on a staged line, and that the GOVERNANCE.md sentence matches what the snippet then does. The Husky.Net snippet and the hub's own .husky/pre-commit judge the working tree by design, so whether an untracked file is in scope there is a separate question.

Done means the repro above passes with the snippet, and a staged violation still fails.