feat(mobile): PinInput component — 6-digit numeric pad

apps/mobile/components/PinInput.test.tsx

@@ -0,0 +1,31 @@
+import { fireEvent, render } from '@testing-library/react-native';
+import { describe, expect, it, vi } from 'vitest';
+
+import { PinInput } from './PinInput';
+
+describe('<PinInput>', () => {
+  it('appends digits to the underlying value and stops at length', () => {
+    const onChange = vi.fn();
+    const { getByTestId } = render(
+      <PinInput value="" onChange={onChange} length={6} ariaLabel="PIN" />,
+    );
+    fireEvent.changeText(getByTestId('pin-input'), '1234567890');
+    expect(onChange).toHaveBeenCalledWith('123456');
+  });
+
+  it('strips non-digits', () => {
+    const onChange = vi.fn();
+    const { getByTestId } = render(
+      <PinInput value="" onChange={onChange} length={6} ariaLabel="PIN" />,
+    );
+    fireEvent.changeText(getByTestId('pin-input'), '1a2b3c');
+    expect(onChange).toHaveBeenCalledWith('123');
+  });
+
+  it('renders one bullet per filled slot', () => {
+    const { getAllByText } = render(
+      <PinInput value="123" onChange={() => {}} length={6} ariaLabel="PIN" />,
+    );
+    expect(getAllByText('•').length).toBe(3);
+  });
+});