fix: Clean up Docker configuration and resolve build issues

- Fix Windows line endings (CRLF) in docker-build.sh script
- Remove deprecated 'version' field from docker-compose.dev.yml
- Standardize database URL paths across compose files
- Optimize Dockerfile.production with better pip upgrade handling
- Improve health check timings for better container startup
- Add comprehensive Docker usage documentation
- Ensure all Docker files use consistent formatting and best practices

All Docker builds now work correctly and containers start successfully.

DOCKER_USAGE.md

@@ -0,0 +1,79 @@
+# Docker Usage Guide
+
+## Quick Start
+
+### Development Environment
+```bash
+# Build and start development container
+docker-compose -f docker-compose.dev.yml up --build
+
+# Or use the build script
+./docker-build.sh
+docker-compose -f docker-compose.dev.yml up
+```
+
+### Production Environment
+```bash
+# Build and start production container
+docker-compose up --build
+
+# Or use the build script
+./docker-build.sh
+docker-compose up
+```
+
+## Available Images
+
+- `delphi-database:dev` - Development image with source code mounting and auto-reload
+- `delphi-database:latest` - Production image optimized for performance
+- `delphi-database:<version>` - Tagged production image with version
+
+## Environment Variables
+
+### Required for Production
+- `SECRET_KEY` - JWT secret key (generate with `openssl rand -base64 32`)
+- `ADMIN_PASSWORD` - Initial admin user password
+
+### Optional Configuration
+- `DATABASE_URL` - Database connection string (default: sqlite:///app/data/delphi_database.db)
+- `DEBUG` - Enable debug mode (default: False for production, True for development)
+- `EXTERNAL_PORT` - External port mapping (default: 6920)
+- `WORKERS` - Number of Gunicorn workers (default: 4)
+- `LOG_LEVEL` - Logging level (default: INFO for production, DEBUG for development)
+
+## Container Access
+
+The application runs on port 8000 inside the container and is mapped to port 6920 on the host by default.
+
+- Application: http://localhost:6920
+- Health check: http://localhost:6920/health
+
+## Data Persistence
+
+### Development
+- Source code: Mounted from host for live reload
+- Database: Docker volume `delphi_dev_data`
+- Uploads: Docker volume `delphi_dev_uploads`
+- Backups: Docker volume `delphi_dev_backups`
+
+### Production
+- Database: Host directory `./data` (for easy backup)
+- Uploads: Docker volume `delphi_uploads`
+- Backups: Docker volume `delphi_backups`
+
+## Troubleshooting
+
+### Container won't start
+1. Check if port 6920 is already in use
+2. Ensure required environment variables are set
+3. Check Docker logs: `docker-compose logs`
+
+### Database issues
+1. Check database file permissions in `./data` directory
+2. Ensure the container can write to mounted volumes
+3. Check initialization logs for admin user creation
+
+### Build failures
+1. Ensure Docker daemon is running
+2. Clear Docker cache: `docker system prune -f`
+3. Rebuild without cache: `docker-compose build --no-cache`