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/calendar/CalendarHeader.tsx

@@ -5,6 +5,7 @@
 
 "use client";
 
+import type { ReactNode } from "react";
 import { Button } from "@/components/ui/button";
 import { useTranslation } from "@/i18n/use-translation";
 import { cn } from "@/lib/utils";
@@ -20,6 +21,8 @@ export interface CalendarHeaderProps {
   disabled?: boolean;
   onPrevMonth: () => void;
   onNextMonth: () => void;
+  /** Optional content shown above the nav row (e.g. Admin link). */
+  trailingContent?: ReactNode;
   className?: string;
 }
 
@@ -28,6 +31,7 @@ export function CalendarHeader({
   disabled = false,
   onPrevMonth,
   onNextMonth,
+  trailingContent,
   className,
 }: CalendarHeaderProps) {
   const { t, monthName, weekdayLabels } = useTranslation();
@@ -37,6 +41,9 @@ export function CalendarHeader({
 
   return (
     <header className={cn("flex flex-col", className)}>
+      {trailingContent != null && (
+        <div className="flex justify-end mb-1 min-h-[1.5rem]">{trailingContent}</div>
+      )}
       <div className="flex items-center justify-between mb-3">
         <Button
           type="button"