Delete a room

Removes a room from active inventory and clears its guest assignments. Cancellation is attempted only after Stripe reports no payment method and no charge; removing a room with a checkout requires confirmed cancellation. Checkout and payment history is retained, including the internal room record when needed by its ledger. Completed or refunded payments, processing payments, active checkouts with a card entered, and checkouts whose cancellation cannot be confirmed return 409 conflict. A payment record or an active or Stripe-linked checkout attempt on another room covered by the same household charge also returns 409; deleting one room never cancels another room's checkout. A successful deletion returns 204; subsequent room reads return 404.