feat: add dedicated TopUpResult page for payment return flow

Replace toast-based payment return with animated result page showing
pending/success/failed/timeout states. Extract shared Spinner,
AnimatedCheckmark and AnimatedCrossmark components. Add sessionStorage
persistence with validation and TTL for cross-redirect payment data.
Unify ProtectedRoute with withLayout prop, add aria-live accessibility.

src/utils/topUpStorage.ts

@@ -0,0 +1,63 @@
+const STORAGE_KEY = 'topup_pending_payment';
+const MAX_AGE_MS = 30 * 60 * 1000; // 30 minutes
+
+export interface TopUpPendingInfo {
+  amount_kopeks: number;
+  method_id: string;
+  method_name: string;
+  payment_id: string;
+  created_at: number; // Date.now()
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null;
+}
+
+export function saveTopUpPendingInfo(info: TopUpPendingInfo) {
+  try {
+    sessionStorage.setItem(STORAGE_KEY, JSON.stringify(info));
+  } catch {
+    // sessionStorage unavailable (private mode, quota, etc.)
+  }
+}
+
+export function loadTopUpPendingInfo(): TopUpPendingInfo | null {
+  try {
+    const raw = sessionStorage.getItem(STORAGE_KEY);
+    if (!raw) return null;
+    const parsed: unknown = JSON.parse(raw);
+    if (
+      !isRecord(parsed) ||
+      typeof parsed.amount_kopeks !== 'number' ||
+      typeof parsed.method_id !== 'string' ||
+      typeof parsed.method_name !== 'string' ||
+      typeof parsed.payment_id !== 'string' ||
+      typeof parsed.created_at !== 'number' ||
+      parsed.amount_kopeks <= 0
+    ) {
+      return null;
+    }
+    // Discard stale entries
+    if (Date.now() - (parsed.created_at as number) > MAX_AGE_MS) {
+      clearTopUpPendingInfo();
+      return null;
+    }
+    return {
+      amount_kopeks: parsed.amount_kopeks as number,
+      method_id: parsed.method_id as string,
+      method_name: parsed.method_name as string,
+      payment_id: parsed.payment_id as string,
+      created_at: parsed.created_at as number,
+    };
+  } catch {
+    return null;
+  }
+}
+
+export function clearTopUpPendingInfo() {
+  try {
+    sessionStorage.removeItem(STORAGE_KEY);
+  } catch {
+    // ignore
+  }
+}