feat: implement AccessDeniedScreen and enhance error handling

- Introduced AccessDeniedScreen component for improved user experience when access is denied, replacing the previous AccessDenied component.
- Updated CurrentDutyView and CalendarPage to handle access denied scenarios, displaying the new screen appropriately.
- Enhanced tests for CurrentDutyView and AccessDeniedScreen to ensure correct rendering and functionality under access denied conditions.
- Refactored localization messages to include new labels for access denied scenarios in both English and Russian.

webapp-next/src/components/current-duty/CurrentDutyView.tsx

@@ -30,6 +30,7 @@ import {
   CardTitle,
 } from "@/components/ui/card";
 import { Skeleton } from "@/components/ui/skeleton";
+import { AccessDeniedScreen } from "@/components/states/AccessDeniedScreen";
 import type { DutyWithUser } from "@/types";
 
 export interface CurrentDutyViewProps {
@@ -39,7 +40,7 @@ export interface CurrentDutyViewProps {
   openedFromPin?: boolean;
 }
 
-type ViewState = "loading" | "error" | "ready";
+type ViewState = "loading" | "error" | "accessDenied" | "ready";
 
 /**
  * Full-screen current duty view with Telegram BackButton and auto-updating remaining time.
@@ -53,6 +54,7 @@ export function CurrentDutyView({ onBack, openedFromPin = false }: CurrentDutyVi
   const [state, setState] = useState<ViewState>("loading");
   const [duty, setDuty] = useState<DutyWithUser | null>(null);
   const [errorMessage, setErrorMessage] = useState<string | null>(null);
+  const [accessDeniedDetail, setAccessDeniedDetail] = useState<string | null>(null);
   const [remaining, setRemaining] = useState<{ hours: number; minutes: number } | null>(null);
 
   const loadTodayDuties = useCallback(
@@ -74,14 +76,17 @@ export function CurrentDutyView({ onBack, openedFromPin = false }: CurrentDutyVi
         }
       } catch (e) {
         if (signal?.aborted) return;
-        setState("error");
-        const msg =
-          e instanceof AccessDeniedError && e.serverDetail
-            ? e.serverDetail
-            : t("error_generic");
-        setErrorMessage(msg);
-        setDuty(null);
-        setRemaining(null);
+        if (e instanceof AccessDeniedError) {
+          setState("accessDenied");
+          setAccessDeniedDetail(e.serverDetail ?? null);
+          setDuty(null);
+          setRemaining(null);
+        } else {
+          setState("error");
+          setErrorMessage(t("error_generic"));
+          setDuty(null);
+          setRemaining(null);
+        }
       }
     },
     [initDataRaw, lang, t]
@@ -195,6 +200,17 @@ export function CurrentDutyView({ onBack, openedFromPin = false }: CurrentDutyVi
     );
   }
 
+  if (state === "accessDenied") {
+    return (
+      <AccessDeniedScreen
+        serverDetail={accessDeniedDetail}
+        primaryAction="back"
+        onBack={handlePrimaryAction}
+        openedFromPin={openedFromPin}
+      />
+    );
+  }
+
   if (state === "error") {
     const handleRetry = () => {
       setState("loading");