feat(pricing): implement tariff management with peak, valley, and flat pricing
feat(api): add tariff API for fetching and updating pricing configurations
feat(tariff-schema): create database schema for tariff configuration
feat(pricing-page): create UI for displaying and managing pricing tiers
fix(sidebar): update sidebar to include pricing settings link
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
