internal/rosa: pass stage alongside state

This cleans up many function signatures.

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

cmd/mbf/main_test.go

@@ -36,7 +36,7 @@ func TestCureAll(t *testing.T) {
 	})
 
 	for _, handle := range rosa.Native().Collect() {
-		a, _ := rosa.Native().MustLoad(rosa.Std, handle)
+		a, _ := rosa.Native().Std().MustLoad(handle)
 		t.Run(rosa.Native().MustGet(handle).Name, func(t *testing.T) {
 			_, err := cureRemote(t.Context(), &addr, a, 0)
 			if err != nil {