feat: enhance testing and admin page functionality

- Mocked `useRouter` from `next/navigation` in tests to improve routing behavior during testing.
- Updated admin page tests to reflect changes in title display and removed unnecessary back link check.
- Refactored admin page header to improve accessibility and layout, displaying month and year more clearly.
- Removed unused imports and components to streamline code and enhance maintainability.

webapp-next/src/app/admin/page.test.tsx

@@ -93,13 +93,12 @@ describe("AdminPage", () => {
     });
   });
 
-  it("shows admin title and back link when allowed and data loaded", async () => {
+  it("shows admin title (month/year) when allowed and data loaded", async () => {
     mockFetchForAdmin();
     render(<AdminPage />);
     await waitFor(() => {
       expect(screen.getByRole("heading", { name: /admin|админка/i })).toBeInTheDocument();
     });
-    expect(screen.getByRole("link", { name: /back to calendar|назад к календарю/i })).toBeInTheDocument();
   });
 
   it("shows access denied when fetchAdminMe returns is_admin false", async () => {

webapp-next/src/app/admin/page.tsx

@@ -6,10 +6,8 @@
 
 "use client";
 
-import Link from "next/link";
 import { useAdminPage, AdminDutyList, ReassignSheet } from "@/components/admin";
 import { useTranslation } from "@/i18n/use-translation";
-import { Button } from "@/components/ui/button";
 import { AccessDeniedScreen } from "@/components/states/AccessDeniedScreen";
 import { LoadingState } from "@/components/states/LoadingState";
 import { ErrorState } from "@/components/states/ErrorState";
@@ -47,24 +45,28 @@ export default function AdminPage() {
           <p className="text-muted-foreground">
             {admin.adminAccessDeniedDetail ?? t("admin.access_denied")}
           </p>
-          <Button asChild variant="outline">
-            <Link href="/">{t("admin.back_to_calendar")}</Link>
-          </Button>
         </div>
       </div>
     );
   }
 
+  const month = admin.currentMonth.getMonth();
+  const year = admin.currentMonth.getFullYear();
+
   return (
     <div className={PAGE_WRAPPER_CLASS}>
-      <header className="sticky top-0 z-10 flex items-center justify-between border-b bg-[var(--header-bg)] py-3">
-        <h1 className="text-lg font-semibold">
-          {t("admin.title")} — {monthName(admin.currentMonth.getMonth())}{" "}
-          {admin.currentMonth.getFullYear()}
+      <header className="sticky top-0 z-10 flex flex-col items-center border-b bg-[var(--header-bg)] py-3">
+        <h1
+          className="m-0 flex flex-col items-center justify-center gap-0 leading-none"
+          aria-label={`${t("admin.title")}, ${monthName(month)} ${year}`}
+        >
+          <span className="text-xs font-normal leading-none text-muted">
+            {year}
+          </span>
+          <span className="text-[1.1rem] font-semibold leading-tight sm:text-[1.25rem]">
+            {monthName(month)}
+          </span>
         </h1>
-        <Button asChild variant="ghost" size="sm">
-          <Link href="/">{t("admin.back_to_calendar")}</Link>
-        </Button>
       </header>
 
       {admin.successMessage && (

webapp-next/src/app/page.test.tsx

@@ -10,6 +10,10 @@ import { resetAppStore } from "@/test/test-utils";
 import { useAppStore } from "@/store/app-store";
 import { useTelegramAuth } from "@/hooks/use-telegram-auth";
 
+vi.mock("next/navigation", () => ({
+  useRouter: () => ({ push: vi.fn(), replace: vi.fn(), prefetch: vi.fn() }),
+}));
+
 vi.mock("@/hooks/use-telegram-auth", () => ({
   useTelegramAuth: vi.fn(),
 }));

webapp-next/src/components/CalendarPage.tsx

@@ -6,14 +6,14 @@
 "use client";
 
 import { useRef, useState, useEffect, useCallback } from "react";
-import Link from "next/link";
+import { useRouter } from "next/navigation";
+import { settingsButton } from "@telegram-apps/sdk-react";
 import { useAppStore } from "@/store/app-store";
 import { useShallow } from "zustand/react/shallow";
 import { useMonthData } from "@/hooks/use-month-data";
 import { useSwipe } from "@/hooks/use-swipe";
 import { useStickyScroll } from "@/hooks/use-sticky-scroll";
 import { useAutoRefresh } from "@/hooks/use-auto-refresh";
-import { useTranslation } from "@/i18n/use-translation";
 import { CalendarHeader } from "@/components/calendar/CalendarHeader";
 import { CalendarGrid } from "@/components/calendar/CalendarGrid";
 import { DutyList } from "@/components/duty/DutyList";
@@ -80,7 +80,7 @@ export function CalendarPage({ isAllowed, initDataRaw }: CalendarPageProps) {
     }))
   );
 
-  const { t } = useTranslation();
+  const router = useRouter();
 
   const { retry } = useMonthData({
     initDataRaw,
@@ -138,6 +138,35 @@ export function CalendarPage({ isAllowed, initDataRaw }: CalendarPageProps) {
     }
   }, [loading, accessDenied, setAppContentReady]);
 
+  // Show native Settings button in Telegram context menu for admins; click navigates to /admin.
+  useEffect(() => {
+    if (!isAdmin) return;
+    let offClick: (() => void) | undefined;
+    try {
+      if (settingsButton.mount.isAvailable()) {
+        settingsButton.mount();
+      }
+      if (settingsButton.show.isAvailable()) {
+        settingsButton.show();
+      }
+      if (settingsButton.onClick.isAvailable()) {
+        offClick = settingsButton.onClick(() => router.push("/admin"));
+      }
+    } catch {
+      // Non-Telegram environment; SettingsButton not available.
+    }
+    return () => {
+      try {
+        if (typeof offClick === "function") offClick();
+        if (settingsButton.hide.isAvailable()) {
+          settingsButton.hide();
+        }
+      } catch {
+        // Ignore cleanup errors in non-Telegram environment.
+      }
+    };
+  }, [isAdmin, router]);
+
   return (
     <div className="content-safe mx-auto flex min-h-[var(--tg-viewport-stable-height,100vh)] w-full max-w-[var(--max-width-app)] flex-col bg-background px-3 pb-6">
       <div
@@ -149,16 +178,6 @@ export function CalendarPage({ isAllowed, initDataRaw }: CalendarPageProps) {
           disabled={navDisabled}
           onPrevMonth={handlePrevMonth}
           onNextMonth={handleNextMonth}
-          trailingContent={
-            isAdmin ? (
-              <Link
-                href="/admin"
-                className="text-sm text-accent hover:underline focus-visible:outline-accent rounded"
-              >
-                {t("admin.link")}
-              </Link>
-            ) : undefined
-          }
         />
         <CalendarGrid
           currentMonth={currentMonth}

webapp-next/src/components/calendar/CalendarHeader.tsx

@@ -5,7 +5,6 @@
 
 "use client";
 
-import type { ReactNode } from "react";
 import { Button } from "@/components/ui/button";
 import { useTranslation } from "@/i18n/use-translation";
 import { cn } from "@/lib/utils";
@@ -21,8 +20,6 @@ export interface CalendarHeaderProps {
   disabled?: boolean;
   onPrevMonth: () => void;
   onNextMonth: () => void;
-  /** Optional content shown above the nav row (e.g. Admin link). */
-  trailingContent?: ReactNode;
   className?: string;
 }
 
@@ -31,7 +28,6 @@ export function CalendarHeader({
   disabled = false,
   onPrevMonth,
   onNextMonth,
-  trailingContent,
   className,
 }: CalendarHeaderProps) {
   const { t, monthName, weekdayLabels } = useTranslation();
@@ -41,9 +37,6 @@ 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"