Add component tests for presentational components and Login

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/components/Button.test.js

@@ -0,0 +1,29 @@
+import { describe, it, expect } from 'vitest';
+import { mount } from '@vue/test-utils';
+import Button from '@/components/Button.vue';
+
+describe('Button', () => {
+  it('renders button text', () => {
+    const wrapper = mount(Button, {
+      props: { buttonText: 'Click Me' },
+    });
+    expect(wrapper.text()).toBe('Click Me');
+  });
+
+  it('adds ring classes on mousedown', async () => {
+    const wrapper = mount(Button, {
+      props: { buttonText: 'Test' },
+    });
+    await wrapper.trigger('mousedown');
+    expect(wrapper.classes()).toContain('ring');
+  });
+
+  it('removes ring classes on mouseup', async () => {
+    const wrapper = mount(Button, {
+      props: { buttonText: 'Test' },
+    });
+    await wrapper.trigger('mousedown');
+    await wrapper.trigger('mouseup');
+    expect(wrapper.classes()).not.toContain('ring');
+  });
+});