Add hashing y verificación de contraseña

mvp/b2c/tests/auth/password.test.ts

@@ -0,0 +1,15 @@
+import { describe, it, expect } from 'vitest';
+import { hashPassword, verifyPassword } from '@/lib/auth/password';
+
+describe('password', () => {
+  it('verifica una contraseña correcta contra su hash', async () => {
+    const hash = await hashPassword('Reforma2026!');
+    expect(hash).not.toBe('Reforma2026!');
+    expect(await verifyPassword('Reforma2026!', hash)).toBe(true);
+  });
+
+  it('rechaza una contraseña incorrecta', async () => {
+    const hash = await hashPassword('Reforma2026!');
+    expect(await verifyPassword('otra', hash)).toBe(false);
+  });
+});