ZIR-000: Add commit message format documentation and tooling

[zeroecco]

Summary

This PR adds comprehensive documentation and tooling to standardize commit messages across the Zirgen project.

Changes

• CONTRIBUTING.md: Added detailed commit message format guidelines

  • Documents the required ZIR-XXX: Description format
  • Provides examples of good and bad commit messages
  • Explains special cases (merge commits, reverts)
  • Includes testing and troubleshooting tips

• scripts/install-commit-msg-hook.sh: Installation script for commit message validation

  • Sets up the existing commit-msg hook
  • Configures a commit message template
  • Makes it easy for contributors to set up validation locally

• .git/commit-msg-template: Commit message template

  • Pre-filled template with format examples
  • Opens automatically when running git commit (without -m)
  • Helps developers write properly formatted messages

Background

The commit-msg hook already exists in the repository at .git/hooks/commit-msg and enforces the ZIR-XXX format. This PR adds the documentation and tooling to make it easier for contributors to:

1. Understand the commit message requirements
2. Install the validation hook locally
3. Use the template to write correct messages

Testing

To test the installation script:

./scripts/install-commit-msg-hook.sh

To test the hook validation:

echo "ZIR-123: Test message" | .git/hooks/commit-msg /dev/stdin

🤖 Generated with Claude Code

Related:

• Nightshift-Task: commit-normalize
• Nightshift-Ref: https://github.com/marcus/nightshift