🖍️ Color n' Constant Changes (#739)

[EightBitByte]

Summary

This WIP PR introduces a styling overhaul for the application's UI, focusing on the Sidebar component and migrating hardcoded colors to CSS variables.

Changes

• Tailwind & CSS Variables: Registered custom CSS variables in globals.css (e.g., surface-elevated, button-primary-bg) and updated tailwind.config.ts.
• Sidebar Component:
  • Restyled SidebarContent to utilize the new color variables and support dark mode consistently.
  • Refactored dietary preference displays to use a new PrefBadge component with distinct semantic colors (red for restrictions, orange for allergies).
  • Improved code structure and readability with the cn utility.
• Toolbar: Adjusted desktop menu dimensions and border radius in DesktopToolbar.
• Fix: Added a missing await to a database insert operation inside packages/api/src/dishes/services.ts.

Closes #739, #727, #734, #728