feat: 3 improvements — hourly toggle position, category rooms panel, period prices in grid

1. BookingModal: move Посуточно/Почасово toggle to top (before dates)
   when room has hourly rate enabled
2. RoomCategoriesPage: Номера > button now expands inline panel
   showing rooms belonging to that category
3. AvailabilityPage:
   - Period prices auto-applied to grid (base → periods → overrides),
     cells from periods show violet П badge
   - П legend item added
   - Hourly rate settings shown in Periods tab for hourly-enabled rooms

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

src/data/ratesData.ts

@@ -21,6 +21,8 @@ export interface PriceCell {
   minNights: number
   channelPrices: Record<string, number> // channelId -> price
   closed: boolean        // закрыто для продажи
+  fromPeriod?: boolean   // цена из ценового периода
+  periodName?: string    // название периода
 }
 
 export interface RatePeriod {