docs: optimize CLAUDE.md for improved readability and MCP integration (#211)

- Reduced file size by 68% (1281 to 405 lines) while preserving all essential information
- Replaced 286 lines of redundant inline examples with concise table referencing examples/ directory
- Consolidated security validation patterns into single comprehensive example
- Streamlined pre-commit section to essential setup and troubleshooting
- Integrated MCP validation throughout with specific Terraform MCP and Context7 commands
- Added MCP-powered validation workflow section for development lifecycle
- Created quick MCP commands reference for common validation tasks
- Removed redundant code examples in favor of directory references
- Maintained all critical development guidelines and best practices

BREAKING CHANGE: None - this is a documentation-only change

Author: lgallard