feat(ext/popup): polish unlock view with logo lockup + glass card

Restructures the unlock screen so the form sits in a glass card with
a primary 'unlock vault' button. Logo, brand, and tagline are grouped
as a lockup. Open-vault and settings are demoted to secondary buttons.
Body gets the .surface-backdrop wrapper.

extension/src/popup/components/__tests__/unlock.test.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { renderUnlock } from '../unlock';
+
+vi.mock('../../../shared/state', () => ({
+  getState: () => ({ loading: false, error: null }),
+  setState: vi.fn(),
+  sendMessage: vi.fn(),
+  navigate: vi.fn(),
+  escapeHtml: (s: string) => s,
+  openVaultTab: vi.fn(),
+}));
+
+describe('renderUnlock', () => {
+  let app: HTMLElement;
+  beforeEach(() => {
+    document.body.innerHTML = '<div id="app"></div>';
+    app = document.getElementById('app')!;
+  });
+
+  it('renders the logo lockup (logo + brand + tagline)', () => {
+    renderUnlock(app);
+    expect(app.querySelector('.brand-logo')).toBeTruthy();
+    expect(app.querySelector('.brand')?.textContent).toBe('Relicario');
+    expect(app.querySelector('.tagline')?.textContent).toContain('two-factor');
+  });
+
+  it('renders the unlock form inside a .glass card', () => {
+    renderUnlock(app);
+    const glass = app.querySelector('.glass');
+    expect(glass).toBeTruthy();
+    expect(glass!.querySelector('#passphrase-input')).toBeTruthy();
+    expect(glass!.querySelector('.btn-primary')).toBeTruthy();
+  });
+
+  it('renders open-vault and settings as secondary buttons outside the card', () => {
+    renderUnlock(app);
+    const vaultBtn = app.querySelector('#vault-btn');
+    const settingsBtn = app.querySelector('#settings-btn');
+    expect(vaultBtn?.classList.contains('btn-secondary')).toBe(true);
+    expect(settingsBtn?.classList.contains('btn-secondary')).toBe(true);
+    // They should NOT be inside the .glass card
+    const glass = app.querySelector('.glass');
+    expect(glass!.contains(vaultBtn!)).toBe(false);
+  });
+});