Fix: Improve Docker Compose configuration and security

[hannes-lehmann]

Fix Docker Compose Configuration Issues

This PR addresses several Docker best practices violations and configuration issues in the all-in-one Docker setup.

Fixes

• Probably closes 🐛 Error running local development with solution #880
• References 🐛 postgres docker container can't start with current docker-compose file #877

Changes Made

🔒 Security & Configuration

• Replaced tracked .env with .env.example - Prevents accidental exposure of credentials in version control
• Added .env to .gitignore - Users now copy .env.example to .env and configure their own keys
• Moved database credentials to environment variables - Supports customization via .env file
• Added missing env variables - APP_EMAIL_LOGO_URL and APP_EMAIL_LOGO_LINK_URL to eliminate startup warnings

🐳 Docker Best Practices

• Pinned image versions - Changed from latest to specific versions:
  • redis:7-alpine (was redis:latest)
  • postgres:16-alpine (was postgres:latest)
• Removed explicit container names - Prevents conflicts when running multiple instances
• Removed unnecessary port exposure - Redis no longer exposes port 6379 to host (only needed internally)
• Removed custom network definition - Uses Docker Compose's default network
• Simplified volume definitions - Removed redundant driver: local (default behavior)
• Added restart policies - All services now have restart: unless-stopped

🔧 Improvements

• Database connection uses env vars - DATABASE_URL now references POSTGRES_USER, POSTGRES_PASSWORD, and POSTGRES_DB
• Default values for all env vars - Falls back to sensible defaults if not specified

Migration Guide

Users upgrading should:

1. Copy .env.example to .env
2. Generate new APP_KEY and JWT_SECRET as documented in the README
3. Customize any other values as needed

Testing

• ✅ Successfully starts all services
• ✅ Database migrations run correctly
• ✅ Application accessible at http://localhost:8123
• ✅ No container name conflicts with other projects
• ✅ Reproducible deployments with pinned versions

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[hannes-lehmann]

I have read the CLA Document and I hereby sign the CLA

[daveearley]

Thanks you very much for this, @hannes-lehmann!