fix(ui): harden power user mode auth checks

ui/tests/unit/components/account/add-account-dialog.test.tsx

@@ -2,6 +2,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import i18n from '@/lib/i18n';
 import { AddAccountDialog } from '@/components/account/add-account-dialog';
 import { render, screen, userEvent, waitFor } from '@tests/setup/test-utils';
+import { toast } from 'sonner';
 
 const authMocks = vi.hoisted(() => ({
   startAuth: vi.fn(),
@@ -35,6 +36,14 @@ vi.mock('@/hooks/use-cliproxy', () => ({
   }),
 }));
 
+vi.mock('sonner', () => ({
+  toast: {
+    success: vi.fn(),
+    error: vi.fn(),
+    warning: vi.fn(),
+  },
+}));
+
 function createJsonResponse(body: Record<string, unknown>): Response {
   return new Response(JSON.stringify(body), {
     status: 200,
@@ -42,7 +51,7 @@ function createJsonResponse(body: Record<string, unknown>): Response {
   });
 }
 
-describe('AddAccountDialog Gemini power user mode', () => {
+describe('AddAccountDialog power user mode', () => {
   const fetchMock = vi.fn<typeof fetch>();
 
   beforeEach(async () => {
@@ -101,4 +110,66 @@ describe('AddAccountDialog Gemini power user mode', () => {
     expect(screen.queryByText('Power user mode enabled')).not.toBeInTheDocument();
     expect(authMocks.startAuth).not.toHaveBeenCalled();
   });
+
+  it('surfaces a power user mode fetch failure and fails closed for Gemini', async () => {
+    fetchMock.mockRejectedValue(new Error('network down'));
+
+    render(
+      <AddAccountDialog open onClose={vi.fn()} provider="gemini" displayName="Gemini" />
+    );
+
+    await waitFor(() =>
+      expect(toast.error).toHaveBeenCalledWith(
+        'Failed to load power user mode settings. Check Settings > Proxy and try again.'
+      )
+    );
+
+    expect(
+      screen.getByText('Failed to load power user mode settings. Check Settings > Proxy and try again.')
+    ).toBeInTheDocument();
+    expect(screen.getByText(/Type exact phrase to continue/i)).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: 'Authenticate' })).toBeDisabled();
+  });
+
+  it('skips the AGY responsibility checklist when power user mode is enabled', async () => {
+    fetchMock.mockResolvedValue(createJsonResponse({ antigravityAckBypass: true }));
+
+    render(<AddAccountDialog open onClose={vi.fn()} provider="agy" displayName="AGY" />);
+
+    await waitFor(() =>
+      expect(fetchMock).toHaveBeenCalledWith('/api/settings/auth/antigravity-risk')
+    );
+
+    const authenticateButton = screen.getByRole('button', { name: 'Authenticate' });
+    await waitFor(() => expect(authenticateButton).toBeEnabled());
+
+    expect(screen.getByText('Power user mode enabled')).toBeInTheDocument();
+    expect(screen.queryByText(/Step 1: I reviewed issue #509/i)).not.toBeInTheDocument();
+
+    await userEvent.click(authenticateButton);
+
+    expect(authMocks.startAuth).toHaveBeenCalledWith(
+      'agy',
+      expect.objectContaining({
+        riskAcknowledgement: undefined,
+      })
+    );
+  });
+
+  it('keeps the AGY responsibility checklist when power user mode is disabled', async () => {
+    fetchMock.mockResolvedValue(createJsonResponse({ antigravityAckBypass: false }));
+
+    render(<AddAccountDialog open onClose={vi.fn()} provider="agy" displayName="AGY" />);
+
+    await waitFor(() =>
+      expect(fetchMock).toHaveBeenCalledWith('/api/settings/auth/antigravity-risk')
+    );
+
+    const authenticateButton = screen.getByRole('button', { name: 'Authenticate' });
+    await waitFor(() => expect(authenticateButton).toBeDisabled());
+
+    expect(screen.getByText(/Step 1: I reviewed issue #509/i)).toBeInTheDocument();
+    expect(screen.queryByText('Power user mode enabled')).not.toBeInTheDocument();
+    expect(authMocks.startAuth).not.toHaveBeenCalled();
+  });
 });