feat: implement admin panel functionality in Mini App

- Added new API endpoints for admin features: `GET /api/admin/me`, `GET /api/admin/users`, and `PATCH /api/admin/duties/:id` to manage user duties.
- Introduced `UserForAdmin` and `AdminDutyReassignBody` schemas for handling admin-related data.
- Updated documentation to include Mini App design guidelines and admin panel functionalities.
- Enhanced tests for admin API to ensure proper access control and functionality.
- Improved error handling and localization for admin actions.

webapp-next/src/components/ui/sheet.tsx

@@ -94,7 +94,7 @@ function SheetContent({
           side === "top" &&
             "inset-x-0 top-0 h-auto border-b data-[state=closed]:slide-out-to-top data-[state=open]:slide-in-from-top",
           side === "bottom" &&
-            "inset-x-0 bottom-0 h-auto border-t data-[state=closed]:slide-out-to-bottom data-[state=open]:slide-in-from-bottom",
+            "inset-x-0 bottom-0 h-auto border-t pb-[calc(24px+var(--tg-viewport-content-safe-area-inset-bottom,env(safe-area-inset-bottom,0px)))] data-[state=closed]:slide-out-to-bottom data-[state=open]:slide-in-from-bottom",
           className
         )}
         {...props}