internal/app: filter ops in implementation

This is cleaner and less error-prone, and should also result in negligibly less memory allocation.

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

internal/app/spwayland.go

@@ -18,6 +18,10 @@ type spWaylandOp struct {
 }
 
 func (s *spWaylandOp) toSystem(state *outcomeStateSys) error {
+	if state.config.Enablements.Unwrap()&hst.EWayland == 0 {
+		return errNotEnabled
+	}
+
 	// outer wayland socket (usually `/run/user/%d/wayland-%d`)
 	var socketPath *check.Absolute
 	if name, ok := state.k.lookupEnv(wayland.WaylandDisplay); !ok {