Visualiser does take command, not filename

support/schemas/generators.cue

@@ -16,7 +16,7 @@ command: !="" & (=~"^[^{}]*(\\{seed(:[0-9]+)?\\}[^{}]*)*$")
 	// Path to solution starts with slash, such as "/submissions/accepted/foo.py"
 	solution?: filepath & =~"^/"
 	// Path to visualiser can be omitted
-	visualizer?:  filepath & =~"^/" | null
+	visualizer?:  command & =~"^/" | null
 	random_salt?: string
 }