feat: add pre-commit workflow for automated code quality

[lgallard]

Summary

Add comprehensive pre-commit GitHub Actions workflow for automated code quality validation and formatting.

• Add pre-commit.yml workflow with Terraform formatting, validation, and linting
• Include terraform-docs for automatic documentation generation
• Add TFLint for advanced Terraform analysis and best practices
• Implement intelligent caching for improved performance
• Add comprehensive documentation section to CLAUDE.md

Features

Automated Code Quality:

• 🔧 Terraform formatting (terraform fmt)
• ✅ Terraform validation (terraform validate)
• 📚 Documentation generation (terraform-docs)
• 🔍 TFLint analysis for best practices
• 🧹 File formatting (trailing whitespace, end-of-file fixes)
• 📋 YAML validation

Performance Optimizations:

• Smart caching of terraform-docs and tflint binaries
• Pre-commit hook caching for faster runs
• Incremental checking on PRs (changed files only)
• 15-minute timeout protection

Test plan

• Validate GitHub Actions workflow syntax
• Test pre-commit workflow triggers (PR and push)
• Verify tool installation and caching behavior
• Confirm incremental file checking works correctly
• Test comprehensive validation on master branch pushes