internal/rosa: read-only access to built-ins

This removes potential footguns caused by mutable builtins without requiring unnecessary clones.

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

cmd/mbf/internal/pkgserver/api.go

@@ -30,7 +30,7 @@ var (
 // handleInfo writes constant system information.
 func handleInfo(w http.ResponseWriter, _ *http.Request) {
 	infoPayloadOnce.Do(func() {
-		infoPayload.Count = len(rosa.Native().Collect())
+		infoPayload.Count = len(rosa.Collect())
 		infoPayload.HakureiVersion = info.Version()
 	})
 	// TODO(mae): cache entire response if no additional fields are planned