more boilerplate and dev environment

frontend/src/lib/models/root.js

@@ -0,0 +1,17 @@
+/**
+ * @typedef {Object} Root
+ * @property {string} objectId
+ * @property {'root'} type
+ * @property {string[]} childIds
+ */
+
+/**
+ * Create a Root object.
+ *
+ * @param {string} objectId
+ * @param {string[]} [childIds=[]]
+ * @returns {Root}
+ */
+export function createRootModel(objectId, childIds = []) {
+	return { objectId, type: 'root', childIds };
+}