Pre-commit hook for linting doesn't run on files modified by `git add -p` (partial staging)

[jamjamgobambam]

When developers stage partial file changes with git add -p, the pre-commit hook lints the entire working tree file instead of only the staged changes, potentially rejecting a commit for unstaged code.

Relevant files:

• .pre-commit-config.yaml

Estimated effort: 2–4 hours