feat: notify admin when never-logged-in user activates account

Sends email to admin when a user with last_login=NULL successfully
sets their password via reset link (first-time activation).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blueprints/auth/routes.py

@@ -1049,9 +1049,26 @@ def reset_password(token):
                 user.verification_token_expires = None
                 logger.info(f"Email auto-verified via password reset for {user.email}")
 
+            # Notify admin if this is a first-time activation (user never logged in)
+            first_activation = user.last_login is None
+
             db.commit()
 
             logger.info(f"Password reset successful for {user.email}")
+
+            if first_activation:
+                try:
+                    import email_service
+                    email_service.send_email(
+                        to=['maciej.pienczyn@inpi.pl'],
+                        subject=f'Aktywacja konta: {user.name}',
+                        body_text=f'{user.name} ({user.email}) właśnie ustawił(a) hasło i aktywował(a) swoje konto w portalu Norda Biznes Partner.',
+                        email_type='admin_notification',
+                        bcc=[]
+                    )
+                except Exception as notify_err:
+                    logger.warning(f"Failed to send activation notification: {notify_err}")
+
             flash('Haslo zostalo zmienione. Mozesz sie teraz zalogowac.', 'success')
             return redirect(url_for('login'))