docs: add comprehensive CLAUDE.md for AI assistant guidance (#59)

Add detailed documentation covering:
- Project architecture and tech stack overview
- Directory structure and component responsibilities
- Development conventions and coding patterns
- Testing guidelines and CI/CD workflows
- Common tasks, troubleshooting, and best practices

This document helps AI assistants understand the codebase structure,
follow project conventions, and make consistent contributions.

Co-authored-by: Claude <noreply@anthropic.com>

Author: JavaZeroo