Update package dependencies to vitest v4.0.16 and enhance role management in auth utilities with new role-checking functions in tests

tests/public-endpoints.spec.ts

@@ -27,6 +27,9 @@ import spielplaeneHandler from '../server/api/spielplaene.get.js'
 
 describe('Öffentliche API-Endpunkte', () => {
   beforeEach(() => {
+    // Setze SMTP-Credentials für Tests
+    process.env.SMTP_USER = 'test@example.com'
+    process.env.SMTP_PASS = 'test-password'
     vi.restoreAllMocks()
     vi.clearAllMocks()
   })