- Centralized and refactored configuration management (`config`) with runtime validation for environment variables.
- Introduced utilities for secure token storage, including AES-GCM encryption and fallback handling.
- Enhanced `authStore` state management with token validation, secure persistence, and initialization from storage.
- Modularized authentication utilities and updated export structure for better maintainability.
- Improved error handling, input validation, and added detailed comments for enhanced clarity.