Trim and lowercase email before storing or attempting login to avoid mismatches from case or surrounding whitespace. Updated RegisteredUserController@store to save 'email' => strtolower(trim($request->email)) and LoginRequest@authenticate to call Auth::attempt with the normalized email input.
When a new user registers with a referral code, their tarifas and promos are now copied from the referring user. Also refactored Usuario_promo and Usuario_tarifa models to use fillable attributes and improved method formatting. Added Swiper CSS/JS to app layout.