internal/rosa/package: migrate remaining trivial packages

The rest are migrated individually.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/stage0.go

@@ -29,31 +29,11 @@ tar \
 	})
 }
 
-func init() {
-	meta := Metadata{
-		Name:        "stage0-dist",
-		Description: "Rosa OS stage0 bootstrap seed",
-		Version:     "20260504",
-	}
-	native.MustRegister(meta.Name, func(t Toolchain) (*Metadata, pkg.Artifact) {
-		return &meta, newTar(
-			"https://hakurei.app/seed/"+meta.Version+"/"+
-				"stage0-"+t.triple()+".tar.bz2",
-			perArch[string]{
-				"amd64":   "IQjFDkiAVLo1XzflgMMiLP3gnVY2hhDMTzl-QqJDCQhcLQ3lLtRzjI5WCxGyW_lk",
-				"arm64":   "6fmwl2Umx2QssKQvxxb1JOGkAjzfA_MXKku0jVdGjYGb35OvwEVA5NYtd0HIy3yH",
-				"riscv64": "Z2ODV0rIoo9iQRUIu35bsaOBeXc_9qQfGcyb2aGneatzNUJlXh5emSpEV2bOklUL",
-			}.unwrap(t.S),
-			pkg.TarBzip2,
-		)
-	})
-}
-
 // HasStage0 returns whether a stage0 distribution is available.
-func HasStage0() (ok bool) {
+func (s *S) HasStage0() (ok bool) {
 	func() {
 		defer func() { ok = recover() == nil }()
-		native.New(stageEarly).Load(stage0Dist)
+		s.New(stageEarly).MustLoad(stage0Dist)
 	}()
 	return
 }