internal/rosa: expose in-place behaviour in generic helper

This change also combines the createDir and wantsDir methods, and replaces the non-inplace target of the generic helper with a deterministic path.

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

internal/rosa/state.go

@@ -746,7 +746,7 @@ func (s *S) getFrame() azalea.Frame {
 			) (v any, set bool, err error) {
 				var attr GenericHelper
 				if err = args.Apply(map[unique.Handle[azalea.Ident]]any{
-					k("mktemp"):  &attr.EnterTemp,
+					k("inPlace"): &attr.InPlace,
 					k("build"):   &attr.Build,
 					k("check"):   &attr.Check,
 					k("install"): &attr.Install,