Processes the move-out for a leasing contract, transitioning it to move_out status.

This endpoint handles the move-out process by:

• Setting the contract end date
• Updating the contract status to move_out
• Creating or updating the move-out inventory
• Generating last month prorated billing items
• Creating refund deposit groups

The end_date and inventory_date parameters specify when the tenant is leaving
and when the inventory inspection occurs.

This is a significant operational action that triggers multiple accounting
and inventory management processes.