add unit tests

this adds the groundwork to start unit testing some modules

src/test/unit/password.spec.ts

@@ -0,0 +1,20 @@
+import { expect, test, describe } from 'vitest';
+import {
+  hashPassword,
+  isPasswordValid,
+  isValidPasswordHash,
+} from '../../server/utils/password';
+
+describe('password', () => {
+  test('password', async () => {
+    const hash = await hashPassword('password');
+
+    await expect(isPasswordValid('password', hash)).resolves.toBe(true);
+    await expect(isPasswordValid('wrong', hash)).resolves.toBe(false);
+
+    expect(isValidPasswordHash('not a hash')).toBe(false);
+    expect(isValidPasswordHash(hash)).toBe(true);
+
+    expect(isValidPasswordHash(hash.replace('argon2', 'argon3'))).toBe(false);
+  });
+});