feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

docs/CONTRIBUTING.md

@@ -0,0 +1,145 @@
+# Contributing to EasyStream
+
+Thank you for your interest in contributing to EasyStream! This document provides guidelines and information for contributors.
+
+## Development Setup
+
+### Prerequisites
+- Docker and Docker Compose
+- PHP 8.2+ (for local development)
+- Node.js (for frontend assets)
+- Git
+
+### Quick Start
+1. Clone the repository
+2. Copy `.env.example` to `.env` and configure
+3. Run `docker-compose up -d --build`
+4. Access the application at `http://localhost:8083`
+
+## Project Structure
+
+### Core Directories
+- `f_core/` - Framework core (classes, functions, configs)
+- `f_modules/` - Feature modules (frontend/backend)
+- `f_templates/` - Smarty templates
+- `f_data/` - Runtime data (logs, cache, uploads)
+- `f_jobs/` - Background job classes
+- `api/` - API endpoints
+- `tests/` - Test suites
+
+### Key Files
+- `index.php` - Main application entry point
+- `docker-compose.yml` - Container orchestration
+- `Caddyfile` - Web server configuration
+- `deploy/srs.conf` - Live streaming server config
+
+## Development Guidelines
+
+### Code Standards
+- Follow PSR-12 coding standards for PHP
+- Use meaningful variable and function names
+- Add PHPDoc comments for all classes and methods
+- Validate all user inputs using `VSecurity` class
+- Use prepared statements for database queries
+
+### Security Best Practices
+- Always use `VSecurity::getParam()` and `VSecurity::postParam()` for input
+- Implement CSRF protection with `csrf_field()` and `validate_csrf()`
+- Escape output with `secure_output()` and `secure_js()`
+- Use rate limiting for sensitive operations
+- Log security events with `VLogger`
+
+### Database Guidelines
+- Use `VDatabase` class for all database operations
+- Validate table and field names
+- Use parameter binding for queries
+- Follow the existing schema patterns
+
+### Testing
+- Write unit tests for new functionality
+- Use PHPUnit for testing
+- Run tests with `./run-tests.sh`
+- Ensure all tests pass before submitting PRs
+
+## Feature Development
+
+### Adding New Features
+1. Create a spec in `.kiro/specs/feature-name/`
+2. Write requirements, design, and tasks
+3. Implement following the task list
+4. Add appropriate tests
+5. Update documentation
+
+### Live Streaming Features
+- Use SRS for RTMP/HLS streaming
+- HLS files are served from `/hls/` endpoint
+- DVR recordings stored in `/srs/rec/`
+- Test streaming with OBS or similar tools
+
+### API Development
+- Follow RESTful principles
+- Use proper HTTP status codes
+- Implement rate limiting
+- Add comprehensive error handling
+- Document all endpoints
+
+## Deployment
+
+### Production Checklist
+- Review `DEPLOYMENT-CHECKLIST.md`
+- Configure environment variables
+- Set up SSL certificates
+- Configure backup procedures
+- Monitor logs and performance
+
+### Docker Deployment
+- Use provided `docker-compose.yml`
+- Configure volumes for persistent data
+- Set up reverse proxy (Caddy included)
+- Configure SRS for live streaming
+
+## Troubleshooting
+
+### Common Issues
+- Check `f_data/logs/` for error logs
+- Verify database connectivity
+- Ensure proper file permissions
+- Check Docker container logs
+
+### Debug Mode
+- Enable debug mode in configuration
+- Use `VLogger` for detailed logging
+- Check admin log viewer for issues
+
+## Getting Help
+
+### Documentation
+- Read the main `README.md`
+- Check `docs/API.md` for API details
+- Review deployment guides in `docs/`
+
+### Support
+- Create GitHub issues for bugs
+- Use discussions for questions
+- Follow the issue templates
+
+## Code Review Process
+
+### Pull Request Guidelines
+1. Create feature branch from `main`
+2. Make focused, atomic commits
+3. Write clear commit messages
+4. Add tests for new functionality
+5. Update documentation as needed
+6. Ensure CI passes
+
+### Review Criteria
+- Code follows project standards
+- Security best practices implemented
+- Tests cover new functionality
+- Documentation is updated
+- No breaking changes without discussion
+
+## License
+
+By contributing to EasyStream, you agree that your contributions will be licensed under the same license as the project.