Add date editing with conflict detection and rental booking editing

- BookingDetailPanel: edit dates/room with inline conflict detection; options to force-save or swap conflicting booking's room
- BookingsPage + CalendarPage: pass rooms/allBookings/onBulkUpdate to panel
- RentalBookingModal: accept editBooking prop to pre-populate fields for editing
- RentalPage: add edit (pencil) button per booking row, unify create/update handler

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

src/pages/CalendarPage.tsx

@@ -33,6 +33,14 @@ export function CalendarPage() {
     }
   }
 
+  const handleBulkUpdate = (updates: Array<{ id: string; data: Partial<Booking> }>) => {
+    setBookings(prev => {
+      let next = [...prev]
+      updates.forEach(u => { next = next.map(b => b.id === u.id ? { ...b, ...u.data } : b) })
+      return next
+    })
+  }
+
   const handleRentalCreate = (b: RentalBooking) => {
     setRentalBookings(prev => [...prev, b])
   }
@@ -45,6 +53,7 @@ export function CalendarPage() {
           bookings={bookings}
           onBookingCreate={handleCreate}
           onBookingUpdate={handleUpdate}
+          onBookingBulkUpdate={handleBulkUpdate}
           fadingBookingIds={fadingBookings}
           rentalObjects={isRentalActive ? RENTAL_OBJECTS : undefined}
           rentalBookings={isRentalActive ? rentalBookings : undefined}