- Added refresh token support in the account model with new fields: refreshToken, refreshTokenExpiry, and tokenVersion.
- Created a new token management utility (utils/tokenManager.js) for generating and verifying access and refresh tokens.
- Updated JWT utility (utils/jwt.js) to maintain backward compatibility while introducing new token generation methods.
- Enhanced middleware for JWT authentication to support new token types and automatic token refreshing.
- Expanded API endpoints in routes/accounts.js to include refresh token functionality, logout options, and token info retrieval.
- Introduced automatic token refresh mechanism in the front-end integration examples.
- Comprehensive migration checklist and documentation for the new refresh token system.
- Added database migration script to accommodate new fields in the Account table.
