[twistedmelonman]

Summary

Fixes #321. The prettier pre-commit hook ran npx prettier --write --ignore-unknown "$@" from the repo root. Prettier resolves a .prettierrc's plugins: entries relative to the process cwd, not the config file that declares them, so any repo with per-package node_modules (no root install) failed to resolve a plugin declared by a nested package's .prettierrc, blocking every commit that touched it.

Changes

• git/hooks/lint-prettier.sh (new): walks each staged file up to its nearest package.json ancestor and runs npx prettier from there, so resolution finds that package's own node_modules. Falls back to the previous behavior (run from the given path) when no package.json ancestor exists. Rejects a resolved relative path that climbs out of the package dir.
• pre-commit/config.yaml: prettier hook's entry now calls $HOME/.config/git/hooks/lint-prettier.sh, matching the existing lint-shell, lint-yamllint, lint-markdown, and lint-zizmor entries (lines 82/101/160/218). The entry falls back to the pre-fix npx prettier call when that script isn't present yet, since lint-prettier.sh is deployed to ~/.config/git/hooks by symlink repair (install.sh), which doesn't run itself — a machine that has pulled this change but not yet re-run install/repair would otherwise hit "No such file" on every prettier commit.
• bash/tests/test-lint-prettier-nested-node-modules.sh (new): known-bad case reproduces the issue's exact repro shape (nested package, no root package.json), then verifies the fixed script resolves the plugin, the no-package.json fallback still formats, no-files exits clean, and the config.yaml entry itself falls back to the old npx prettier codepath (proven via a stub npx) when the script isn't installed.

Note on local review

The commit-time reviewer initially flagged the $HOME/... entry form as a BLOCKING false positive ("$HOME not expanded"), on two separate commit attempts. This is disproven by:

• Four already-merged entries in the same file using the byte-identical bash -c '$HOME/...' -- form (lines 82/101/160/218, from PRs fix(zizmor): resolve config the way CI does instead of leaving it to discovery #344/feat(hooks): resolve yamllint config the way CI does #347/docs(hooks): cite run-standards.sh blocks by name, not by line number #349).
• Direct proof that bash -c expands $HOME at runtime when executing the single-quoted -c string (verified against a nonexistent path — the error showed the fully-expanded path, not a literal $HOME).
• Test case 4 in the new test file exercises this exact codepath with a controlled HOME and confirms expansion works.

On the third commit attempt the adversarial-reviewer returned PASS and correctly identified the code-reviewer's claim as false; the arbiter sided with it and the commit went through on its own merits, not via a bypass.

Test plan

• Known-bad case reproduces (plugin fails to resolve from repo root)
• bash bash/tests/run-tests.sh — 34/34 passed
• shellcheck -S info clean, no disable directives
• Pre-push full-diff review: PASS
• Pre-push full test suite: 34/34 passed

[claude]

New lint-prettier.sh hook resolves Prettier plugins from the nearest package.json ancestor directory, fixing the plugin resolution failure from #321. The >- YAML folding in config.yaml correctly collapses the multiline entry to a single shell command. The .. traversal guard is sound. The fallback when no package.json ancestor exists preserves the prior behavior. No BLOCK-level issues found.

VERDICT: PASS