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

tests/canvas-node-favorite.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  preserveNodeFavorite,
+  readNodeFavorite,
+  setNodeFavorite,
+} from "@/lib/canvas-node-favorite";
+
+describe("canvas node favorite helpers", () => {
+  it("reads favorite from object data", () => {
+    expect(readNodeFavorite({ isFavorite: true })).toBe(true);
+  });
+
+  it("returns false when favorite flag is missing", () => {
+    expect(readNodeFavorite({})).toBe(false);
+  });
+
+  it("persists favorite when enabled", () => {
+    expect(setNodeFavorite(true, { label: "Frame" })).toEqual({
+      label: "Frame",
+      isFavorite: true,
+    });
+  });
+
+  it("removes favorite key when disabled", () => {
+    expect(setNodeFavorite(false, { label: "Frame", isFavorite: true })).toEqual({
+      label: "Frame",
+    });
+  });
+
+  it("preserves favorite after strict normalization", () => {
+    expect(
+      preserveNodeFavorite(
+        {
+          crop: {
+            x: 0,
+            y: 0,
+            width: 1,
+            height: 1,
+          },
+        },
+        { isFavorite: true },
+      ),
+    ).toEqual({
+      crop: {
+        x: 0,
+        y: 0,
+        width: 1,
+        height: 1,
+      },
+      isFavorite: true,
+    });
+  });
+});