feat(auth): transition from email to phone-based OTP authentication

- Replace Email+Password login with Phone+OTP flow
- Remove RegisterCubit and registration screens (email verification)
- Remove ResetPasswordCubit and reset password screens
- Add phone normalization and international dial code support
- Update LoginCubit with sendCode/resend cooldown logic
- Add new widgets: phone prefix selector, confirm sheet
- Update all auth API endpoints: /otp/send, /phone-session
- Update form inputs: Email -> Phone with E.164 validation
- Update tests for new auth flow

apps/lib/core/router/app_routes.dart

@@ -3,9 +3,6 @@ class AppRoutes {
 
   static const authBoot = '/boot';
   static const authLogin = '/';
-  static const authRegister = '/register';
-  static const authRegisterVerification = '/register/verification';
-  static const authResetPassword = '/reset-password';
 
   static const homeMain = '/home';
 
@@ -31,6 +28,5 @@ class AppRoutes {
   static const settingsFeatures = '/settings/features';
   static const settingsMemory = '/settings/memory';
   static const settingsAccount = '/settings/account';
-  static const settingsChangePassword = '/change-password';
   static const settingsEditProfile = '/edit-profile';
 }