IAV-[563]- feat(auth): Implement modular register component architecture -

Register Component Architecture

- Create modular register page structure reducing complexity
- Implement RegisterForm with Formik validation and Zustand store integration
- Build reusable sub-components: RegisterHeader, RegisterNameFields, RegisterPhoneField, RegisterPasswordFields, RegisterButton, RegisterFooter
- Integrate with existing AuthLayout and GuestGuard for consistent auth flow

Component Features

- Add first name and last name fields with Grid layout for responsive design
- Implement phone number field with international format placeholder
- Create password and confirm password fields with visibility toggles
- Add glassmorphism styling consistent with login components
- Include loading states and error handling with ConditionalComponent pattern

Form Validation & Submission

- Integrate registerValidationSchema for client-side validation
- Handle form submission with createAdmin action from user store
- Redirect to login page on successful registration
- Display server errors with styled Alert component

Code Quality

- Use ConditionalComponent pattern for conditional rendering
- Extract shared field styles for consistency
- Maintain component modularity for better maintainability
- Follow existing auth component patterns and naming conventions

CLOSE-[563]