feat(canvas): add persistent node favorites with toolbar star and glow

lib/canvas-node-favorite.ts

@@ -0,0 +1,36 @@
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function toRecord(value: unknown): Record<string, unknown> {
+  return isRecord(value) ? value : {};
+}
+
+export function readNodeFavorite(data: unknown): boolean {
+  const source = toRecord(data);
+  return source.isFavorite === true;
+}
+
+export function setNodeFavorite(
+  nextValue: boolean,
+  currentData: unknown,
+): Record<string, unknown> {
+  const source = toRecord(currentData);
+
+  if (nextValue) {
+    return {
+      ...source,
+      isFavorite: true,
+    };
+  }
+
+  const { isFavorite: _isFavorite, ...rest } = source;
+  return rest;
+}
+
+export function preserveNodeFavorite(
+  nextData: unknown,
+  previousData: unknown,
+): Record<string, unknown> {
+  return setNodeFavorite(readNodeFavorite(previousData), nextData);
+}