feat(auth): add logging for user registration and activation email process

- Introduced console logging to track the registration flow, including the generated activation code and confirmation of user creation and email sending.
- This enhancement aids in debugging and monitoring the registration process without altering the existing functionality.

backend/services/authService.js

@@ -8,12 +8,15 @@ import { devLog, errorLog } from '../utils/logger.js';
 
 const register = async (email, password) => {
   try {
+    console.log('register', email, password);
     const activationCode = Math.random().toString(36).substring(2, 15);
+    console.log('activationCode', activationCode);
     await User.create({ email, password, activationCode });
+    console.log('User created');
 
     // Aktivierungs‑E-Mail versenden
     await sendActivationEmail(email, activationCode);
-
+    console.log('Activation email sent');
     // Aufrufer bekommt absichtlich KEINE Userdaten zurück (siehe Controller)
     return;
   } catch (error) {