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.

CONTRIBUTING.md

@@ -0,0 +1,160 @@
+# Contributing to PicPeak
+
+First off, thank you for considering contributing to PicPeak! It's people like you that make PicPeak such a great tool for photographers worldwide.
+
+## 🤝 Code of Conduct
+
+This project and everyone participating in it is governed by the [PicPeak Code of Conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code.
+
+## 🎯 How Can I Contribute?
+
+### Reporting Bugs
+
+Before creating bug reports, please check the existing issues as you might find out that you don't need to create one. When you are creating a bug report, please include as many details as possible:
+
+* **Use a clear and descriptive title**
+* **Describe the exact steps to reproduce the problem**
+* **Provide specific examples to demonstrate the steps**
+* **Describe the behavior you observed and what you expected**
+* **Include screenshots if possible**
+* **Include your environment details** (OS, browser, Docker version, etc.)
+
+### Suggesting Enhancements
+
+Enhancement suggestions are tracked as GitHub issues. When creating an enhancement suggestion, please include:
+
+* **Use a clear and descriptive title**
+* **Provide a detailed description of the suggested enhancement**
+* **Provide specific examples to demonstrate the enhancement**
+* **Describe the current behavior and expected behavior**
+* **Explain why this enhancement would be useful**
+
+### Your First Code Contribution
+
+Unsure where to begin? You can start by looking through these issues:
+
+* [Good first issues](https://github.com/the-luap/picpeak/labels/good%20first%20issue) - issues which should only require a few lines of code
+* [Help wanted issues](https://github.com/the-luap/picpeak/labels/help%20wanted) - issues which need extra attention
+
+### Pull Requests
+
+1. **Fork the repo** and create your branch from `main`
+2. **Install dependencies**:
+   ```bash
+   cd backend && npm install
+   cd ../frontend && npm install
+   ```
+3. **Make your changes** and ensure:
+   - Code follows the existing style
+   - Tests pass: `npm test`
+   - Linting passes: `npm run lint`
+4. **Write tests** if you've added code
+5. **Update documentation** if needed
+6. **Create a Pull Request**
+
+## 💻 Development Setup
+
+### Prerequisites
+
+- Node.js 18+
+- Docker & Docker Compose
+- Git
+
+### Local Development
+
+```bash
+# Clone your fork
+git clone https://github.com/your-username/picpeak.git
+cd picpeak
+
+# Install dependencies
+cd backend && npm install
+cd ../frontend && npm install
+
+# Set up environment
+cp .env.example .env
+# Edit .env with your settings
+
+# Start development servers
+docker-compose -f docker-compose.dev.yml up
+```
+
+### Running Tests
+
+```bash
+# Backend tests
+cd backend && npm test
+
+# Frontend tests
+cd frontend && npm test
+
+# E2E tests
+npm run test:e2e
+```
+
+## 📝 Styleguides
+
+### Git Commit Messages
+
+* Use the present tense ("Add feature" not "Added feature")
+* Use the imperative mood ("Move cursor to..." not "Moves cursor to...")
+* Limit the first line to 72 characters or less
+* Reference issues and pull requests liberally after the first line
+* Consider starting the commit message with an applicable emoji:
+  * 🎨 `:art:` when improving the format/structure of the code
+  * 🐛 `:bug:` when fixing a bug
+  * 🔥 `:fire:` when removing code or files
+  * 📝 `:memo:` when writing docs
+  * 🚀 `:rocket:` when improving performance
+  * ✨ `:sparkles:` when adding a new feature
+
+### JavaScript/TypeScript Styleguide
+
+* Use ES6+ features
+* Prefer async/await over promises
+* Use meaningful variable names
+* Add JSDoc comments for functions
+* Follow ESLint rules
+
+### React Styleguide
+
+* Use functional components with hooks
+* Keep components small and focused
+* Use TypeScript for type safety
+* Follow the existing folder structure
+* Write tests for new components
+
+## 📦 Project Structure
+
+```
+picpeak/
+├── backend/
+│   ├── src/
+│   │   ├── routes/      # API endpoints
+│   │   ├── services/    # Business logic
+│   │   ├── middleware/  # Express middleware
+│   │   └── utils/       # Utilities
+│   └── migrations/      # Database migrations
+├── frontend/
+│   ├── src/
+│   │   ├── components/  # Reusable components
+│   │   ├── pages/       # Page components
+│   │   ├── services/    # API services
+│   │   └── hooks/       # Custom hooks
+│   └── public/          # Static assets
+```
+
+## 🔄 Release Process
+
+1. Update version numbers in package.json files
+2. Update CHANGELOG.md
+3. Create a new release on GitHub
+4. Docker images are automatically built and published
+
+## 📮 Contact
+
+- Create an issue for bugs or features
+- Join discussions for questions
+- Email: picpeak@example.com for security issues
+
+Thank you for contributing! 🎉