internal/rosa: evaluate packages from fs

This migrates GNU sed to azalea, and resulting IR matches.

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

internal/rosa/rosa.go

@@ -2,6 +2,9 @@
 package rosa
 
 import (
+	"embed"
+	"io/fs"
+	"os"
 	"path"
 	"slices"
 	"strconv"
@@ -608,3 +611,20 @@ var native S
 
 // Native returns the global [S].
 func Native() *S { return &native }
+
+// nativeB is the backing directory of built-in azalea-based [Artifact]
+// implementations.
+//
+//go:embed package
+var nativeB embed.FS
+
+func init() {
+	sub, err := fs.Sub(nativeB, "package")
+	if err != nil {
+		panic(err)
+	}
+	if err = native.EvaluateFS(sub); err != nil {
+		println(err)
+		os.Exit(1)
+	}
+}