Sable Sands PMS - Next Pack

Added in this pack:
- modules/reservations/reservation_form.php
- updated reservation_list.php with Create/Edit buttons
- modules/calendar/availability_planner.php
- modules/calendar/move_booking.php
- sidebar and CSS/JS updates for planner and forms

Notes:
1. This pack assumes these tables exist and are populated:
   orders, guests, agents, room_types, rooms, services, rel_orders_services, rel_orders_prices, occassions.
2. The reservation form writes nightly room rows into rel_orders_prices.
3. The planner allows drag-drop room reassignment and updates both orders.room_id and rel_orders_prices.room_id.
4. If your services table uses a different amount column name than `amount`, adjust the services query in reservation_form.php.
5. If rel_orders_services has different column names than used here (service_id, date, guest, adults, amount, notes), adjust the INSERT accordingly.
