The project no longer relies on nixos-generators for virtual images, so
the badge is misleading.
fix(system): prefer special format handlers
Ensure formats like iso and docker use their module-backed builders even
when image variants exist.
BREAKING CHANGE
This commit modifies the overlay builder's original behavior
in a non-backward compatible way. Previously, all overlays
would be namespaced with "nixpkgs/". This was often
unnecessary or would cause conflicts with package overlays if
they shared a name. After this change, all overlays retain their
directory name (eg. "my-overlay") and all package overlays are
prefixed with "package/" to differentiate them and avoid name
conflicts.
