docs: major repository restructure for GitHub public release

- Create comprehensive README.md optimized for GitHub/SEO
- Consolidate deployment instructions into single DEPLOYMENT.md
- Add all standard GitHub documentation files:
  - CONTRIBUTING.md with development guidelines
  - CODE_OF_CONDUCT.md for community standards
  - SECURITY.md with vulnerability reporting
  - CHANGELOG.md following Keep a Changelog format
- Simplify deployment with single docker-compose.yml
- Remove complex deployment configurations (Swarm, Traefik)
- Add backup script for easy maintenance
- Update .github-mirror-exclude to hide complex configs
- Remove redundant documentation files

This prepares PicPeak as a professional open-source alternative
to PicDrop and Scrapbook.de with clear, simple deployment.

CHANGELOG.md

@@ -0,0 +1,66 @@
+# Changelog
+
+All notable changes to PicPeak will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+- Gitea workflows for selective GitHub mirroring
+- Password visibility toggle on event creation form
+- Translation for password requirement errors
+
+### Changed
+- Relaxed password requirements from 12 to 8 characters minimum
+- Made special characters optional for gallery passwords
+- Improved password strength requirements for better usability
+
+### Fixed
+- Production deployment issues with Traefik routing
+- Database migration failures for email_queue table
+- JSON parsing errors in production environment
+- PostgreSQL compatibility issues
+- Connection stability in production
+
+## [1.0.22] - 2024-01-14
+
+### Added
+- Comprehensive error boundaries for better error handling
+- Skeleton loading screens for improved perceived performance
+- Offline indicator for network status
+- Keyboard navigation support in gallery lightbox
+- Skip links for accessibility
+- Focus trap management for modals
+
+### Changed
+- Improved accessibility to WCAG 2.1 AA compliance
+- Enhanced loading states with skeleton screens
+- Better error recovery with component-level boundaries
+
+### Fixed
+- Missing translations in German locale
+- Session timeout caching issues
+- Email template JSON parsing errors
+
+## [1.0.0] - 2024-01-01
+
+### Added
+- Initial release of PicPeak
+- Photo gallery management system
+- Automatic file watching and gallery creation
+- Password-protected galleries
+- Expiration system with email notifications
+- Admin dashboard with analytics
+- Multi-language support (EN, DE)
+- Docker deployment support
+- Email template customization
+- User upload functionality
+- Bulk download features
+- Mobile-responsive design
+- Theme customization options
+
+[Unreleased]: https://github.com/the-luap/picpeak/compare/v1.0.22...HEAD
+[1.0.22]: https://github.com/the-luap/picpeak/compare/v1.0.0...v1.0.22
+[1.0.0]: https://github.com/the-luap/picpeak/releases/tag/v1.0.0