Add pre-commit CI integration to GitHub Actions workflow

[aightmunam]

Summary

This PR adds pre-commit CI integration to the dotfiles repository, enhancing code quality and consistency checks.

Changes Made

1. Added .pre-commit-config.yaml

• Configured pre-commit hooks for multiple file types:
  • YAML: Syntax checking with check-yaml
  • TOML: Syntax checking with check-toml
  • Shell scripts: Linting with shellcheck (two implementations for comprehensive coverage)
  • Lua files: Linting with vint
  • General: End-of-file fixer, trailing whitespace removal, mixed line ending fixes

2. Updated GitHub Actions Workflow

• Added new pre-commit job to .github/workflows/dotfiles-ci.yml
• The job performs the following:
  • Sets up Python environment
  • Installs pre-commit
  • Runs all configured hooks on all files
• Updated the validation job to depend on the new pre-commit job

Benefits

• Automated quality checks: Pre-commit hooks run automatically in CI
• Multi-format support: Covers YAML, TOML, shell, Lua, and config files
• Consistency: Ensures all code meets quality standards before merging
• Early detection: Catches syntax errors and formatting issues before manual review

Testing

The workflow will run automatically on this PR to verify all checks pass.