feat(dayjs): integrate dayjs for date handling and formatting across the application
refactor(routes): update date handling in id-tags, transactions, users, and dashboard routes to use dayjs
style(globals): improve CSS variable definitions for better readability and consistency
deps: add dayjs as a dependency for date manipulation
feat(auth): implement login page and authentication middleware
feat(sidebar): create sidebar component with user info and navigation links
feat(api): establish API client for interacting with backend services
