Add WS reconnect logic + connection indicator in calendar

- useHotelSocket: reconnect with exponential backoff (up to 30s), return connected state, log errors to console
- BookingCalendar: show green/gray dot + Online/Offline label in toolbar
- CalendarPage: pass wsConnected prop

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/calendar/BookingCalendar.tsx

@@ -31,6 +31,7 @@ interface BookingCalendarProps {
   locks?: Map<string, BookingLock>
   onDraftStart?: (roomId: string, checkIn: string, checkOut: string) => void
   onDraftCancel?: (roomId: string) => void
+  wsConnected?: boolean
 }
 
 const CATEGORY_ORDER: Record<string, number> = {
@@ -54,7 +55,7 @@ function getRoomTypeColor(type: string): string {
   return map[type] ?? 'bg-slate-100 text-slate-600 dark:bg-slate-700 dark:text-slate-300'
 }
 
-export function BookingCalendar({ rooms, bookings, onBookingCreate, onBookingUpdate, onBookingBulkUpdate, fadingBookingIds, rentalObjects, rentalBookings, onRentalBookingCreate, locks = new Map(), onDraftStart, onDraftCancel }: BookingCalendarProps) {
+export function BookingCalendar({ rooms, bookings, onBookingCreate, onBookingUpdate, onBookingBulkUpdate, fadingBookingIds, rentalObjects, rentalBookings, onRentalBookingCreate, locks = new Map(), onDraftStart, onDraftCancel, wsConnected }: BookingCalendarProps) {
   const [startDate, setStartDate] = useState(() => startOfDay(new Date()))
   const [visibleDays, setVisibleDays] = useState(DAYS_VISIBLE)
 
@@ -266,6 +267,20 @@ export function BookingCalendar({ rooms, bookings, onBookingCreate, onBookingUpd
           ))}
         </div>
 
+        {/* WebSocket status indicator */}
+        {wsConnected !== undefined && (
+          <div
+            className="flex items-center gap-1.5 px-2 py-1 rounded-lg text-xs text-slate-400 dark:text-slate-500"
+            title={wsConnected ? 'Синхронизация активна' : 'Нет соединения — переподключение...'}
+          >
+            <span className={cn(
+              'w-1.5 h-1.5 rounded-full',
+              wsConnected ? 'bg-emerald-500' : 'bg-slate-300 dark:bg-slate-600 animate-pulse',
+            )} />
+            <span className="hidden sm:inline">{wsConnected ? 'Онлайн' : 'Офлайн'}</span>
+          </div>
+        )}
+
         <button
           onClick={() => setCompact(v => { const next = !v; localStorage.setItem('calendarCompact', String(next)); return next })}
           title={compact ? 'Обычный вид' : 'Компактный вид'}