feat(renderer): add useAppStore with sidebar/preview/zen/pane-sizes

tests/unit/stores/app-store.test.ts

@@ -0,0 +1,35 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { useAppStore } from '@/stores/app-store';
+
+describe('useAppStore', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    useAppStore.setState({
+      sidebarVisible: true,
+      previewVisible: true,
+      zenMode: false,
+      paneSizes: { sidebar: 20, editor: 50, preview: 30 },
+    });
+  });
+
+  it('toggles sidebar visibility', () => {
+    expect(useAppStore.getState().sidebarVisible).toBe(true);
+    useAppStore.getState().toggleSidebar();
+    expect(useAppStore.getState().sidebarVisible).toBe(false);
+  });
+
+  it('toggles preview visibility', () => {
+    useAppStore.getState().togglePreview();
+    expect(useAppStore.getState().previewVisible).toBe(false);
+  });
+
+  it('updates pane sizes', () => {
+    useAppStore.getState().setPaneSizes({ sidebar: 25, editor: 50, preview: 25 });
+    expect(useAppStore.getState().paneSizes).toEqual({ sidebar: 25, editor: 50, preview: 25 });
+  });
+
+  it('enables and disables zen mode', () => {
+    useAppStore.getState().setZenMode(true);
+    expect(useAppStore.getState().zenMode).toBe(true);
+  });
+});