pac-validate

# Validate PAC Structure

Validate Product as Code project structure and files for specification compliance

## Instructions

1. **Initial Environment Check**
   - Verify `.pac/` directory exists
   - Check for PAC configuration file at `.pac/pac.config.yaml`
   - Parse arguments: `$ARGUMENTS`
   - Determine validation scope (single file, directory, or entire project)

2. **Configuration Validation**
   - Load and validate `.pac/pac.config.yaml`:
     - Check `apiVersion` format (must be semanti