This PR changes all mentions of GHCR to Quay, adds docs about the
registries MM is available on, adds docs about the available docker
image tags, and adds the GHCR permission issue to the troubleshooting
page.
- Move images directory from /data/images to /app/images to separate app data from user media
- Implement config folder approach instead of direct file mounting
- Add automatic config initialization with example config on first boot
- Remove hardcoded media directory environment variables from Dockerfile
- Update startup script to handle config folder setup and validation
- Only create application-managed directories, not user media directories
- Update docker-compose.yaml to use config folder volume mapping
Fixes container startup failures when config.toml doesn't exist and improves
separation between application data and user media directories.
