fix(auth): retain input on failure + copy fixes

apps/next/tests/component/sign-in-retention.test.tsx

@@ -0,0 +1,49 @@
+import { fireEvent, render, screen, waitFor } from '@testing-library/react';
+import { describe, expect, it, vi } from 'vitest';
+
+import SignIn from '../../src/app/(auth)/sign-in/page';
+
+const { mockSignIn, mockToastError } = vi.hoisted(() => ({
+  mockSignIn: vi.fn(),
+  mockToastError: vi.fn(),
+}));
+
+vi.mock('@convex-dev/auth/react', () => ({
+  useAuthActions: () => ({ signIn: mockSignIn }),
+}));
+
+vi.mock('next/navigation', () => ({
+  useRouter: () => ({ push: vi.fn(), replace: vi.fn() }),
+}));
+
+vi.mock('sonner', () => ({
+  toast: {
+    error: mockToastError,
+    success: vi.fn(),
+  },
+}));
+
+describe('sign-in input retention', () => {
+  it('keeps the typed email and password after a failed sign-in', async () => {
+    mockSignIn.mockRejectedValue(new Error('Invalid credentials'));
+
+    render(<SignIn />);
+
+    const emailInput = screen.getByPlaceholderText('you@example.com');
+    const passwordInput = screen.getByPlaceholderText('Your password');
+
+    fireEvent.change(emailInput, {
+      target: { value: 'person@example.com' },
+    });
+    fireEvent.change(passwordInput, { target: { value: 'Sup3rSecret!' } });
+
+    fireEvent.click(screen.getByRole('button', { name: 'Sign In' }));
+
+    await waitFor(() => expect(mockToastError).toHaveBeenCalled());
+
+    await waitFor(() => {
+      expect(emailInput).toHaveValue('person@example.com');
+      expect(passwordInput).toHaveValue('Sup3rSecret!');
+    });
+  });
+});