- Use .sources format instead of sources.list
- Add both deb and deb-src types to enable apt source command
- This fixes the CI build failure where apt source ostree was failing
- Removed libavahi-ui-gtk3-0-dev and related packages that don't exist in Debian unstable
- Kept essential Avahi development packages for OSTree build
- Added comprehensive debugging to CI workflow
- Added mk-build-deps to automatically install build dependencies