feat: widget rental tab — real objects, time slots, actual rental_bookings

- Add rental_objects to /api/widget/:slug/config response
- Add POST /api/widget/:slug/rental-bookings endpoint with availability check
- Widget rental tab now shows real rental objects (not additionalServices)
- Date picker, hourly or full-day toggle, start/end hour selectors
- Booking submit creates actual rental_booking record in DB
- Success screen shows rental object, date and time slot
- WidgetRentalObject + WidgetRentalBookingPayload types added to api.ts
- BookingWidgetStandalonePage passes rentalObjects to WidgetPreview

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

src/lib/api.ts

@@ -885,6 +885,16 @@ export const api = {
         return r.json() as Promise<{ first_name: string; last_name: string; middle_name?: string; email?: string; phone?: string; is_blacklisted: boolean }>
       })
     },
+    createRentalBooking: (slug: string, data: WidgetRentalBookingPayload) =>
+      fetch(`${BASE}/api/widget/${slug}/rental-bookings`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(data),
+      }).then(async r => {
+        const json = await r.json()
+        if (!r.ok) throw { status: r.status, ...json }
+        return json as { bookingId: string; status: string }
+      }),
   },
 }
 
@@ -1662,6 +1672,31 @@ export interface WidgetCategory {
   maxGuests: number
 }
 
+export interface WidgetRentalObject {
+  id: string
+  name: string
+  icon: string
+  pricePerHour: number
+  pricePerDay: number
+  openHour: number
+  closeHour: number
+  maxHoursPerSlot: number | null
+  bufferMinutes: number
+}
+
+export interface WidgetRentalBookingPayload {
+  objectId: string
+  date: string
+  isFullDay?: boolean
+  startHour?: number
+  endHour?: number
+  guestName: string
+  guestEmail?: string
+  guestPhone?: string
+  totalAmount: number
+  notes?: string
+}
+
 export interface WidgetConfig {
   hotelId: string
   hotelName: string
@@ -1670,6 +1705,7 @@ export interface WidgetConfig {
   currency: string
   rooms: WidgetRoom[]
   categories: WidgetCategory[]
+  rentalObjects?: WidgetRentalObject[]
   widgetSettings?: {
     primaryColor: string
     language: string