fix: harden web ui self-update restart (#552)

tests/client/app-store.test.ts

@@ -33,4 +33,17 @@ describe('App Store', () => {
     expect(store.sidebarCollapsed).toBe(false)
     expect(window.localStorage.getItem('hermes_sidebar_collapsed')).toBe('0')
   })
+
+  it('clears the updating state and reports failure when self-update request fails', async () => {
+    const consoleError = vi.spyOn(console, 'error').mockImplementation(() => {})
+    mockSystemApi.triggerUpdate.mockRejectedValue(new Error('install failed'))
+    const store = useAppStore()
+
+    const ok = await store.doUpdate()
+
+    expect(ok).toBe(false)
+    expect(store.updating).toBe(false)
+    expect(consoleError).toHaveBeenCalledWith('Failed to update Hermes Web UI:', expect.any(Error))
+    consoleError.mockRestore()
+  })
 })