test(10-13): regression tests for all 6 UAT gaps

- keyboard.test.js: Gap 4 test — matched.find(r => r.instances?.default) resolves to FileManagerView
- TreeItem.test.js: Gap 1 tests — animate-pulse present, 'Loading' text absent during shimmer state
- StorageBrowser.showSearch.test.js: Gap 2 tests — showSearch true for local+cloud at root
- All 219 tests pass (8 new, 211 existing)

frontend/src/__tests__/keyboard.test.js

@@ -136,3 +136,24 @@ describe('UX-08: "N" starts new folder input', () => {
     expect(() => w.vm.startNewFolder()).not.toThrow()
   })
 })
+
+describe('Gap 4: getFileManagerInstance resolves to actual component, not RouterView proxy', () => {
+  it('matched.find(r => r.instances?.default) returns an object with focusSearch defined when mounted via router-view', async () => {
+    setActivePinia(createPinia())
+    const router = makeRouter()
+    await router.push('/')
+    await router.isReady()
+    // Mount via a router-view wrapper so Vue Router populates r.instances.default
+    const { defineComponent, h } = await import('vue')
+    const { RouterView } = await import('vue-router')
+    const App = defineComponent({ render: () => h(RouterView) })
+    mount(App, {
+      global: { plugins: [router], stubs: { QuotaBar: true, AppSpinner: true } },
+    })
+    await flushPromises()
+    const instance = router.currentRoute.value.matched.find(r => r.instances?.default)?.instances?.default
+    expect(instance).not.toBeNull()
+    expect(instance).toBeDefined()
+    expect(typeof instance.focusSearch).toBe('function')
+  })
+})