Steps to reproduce:
- More products/customers than the loading limits (or a product made unavailable in PoS after its order was placed)
- Sell such a product to such a customer, close the order
- Reopen the ticket screen in a fresh session and open the paid order

Issue:
The order shows without its orderlines (silently deleted), so it cannot be refunded correctly. Its customer is blank: a refund loses the partner and invoicing asks to pick a customer again.

Cause:
Since 64ca0e5e924a the ticket screen fetches paid orders through `callRelated("pos.order", "get_ticket_screen_order_data")` instead of `data.read("pos.order", ids)`. `read` is part of
`autoLoadedOrmMethods`, so `missingRecursive()` fetched the products and partners referenced by the orders; `callRelated` loads the payload as-is, and `read_pos_data()` includes neither `product.product` nor
`res.partner` records. An orderline whose product is not in the store is deleted by its `setup()`, and an unknown `partner_id` stays unresolved.

Fix:
Send the orderlines' products and the orders' partners along in `get_ticket_screen_order_data()`: `loadData()` links the records before the orderlines' `setup()` runs, so the frontend keeps them. Server-side only, no API change; 19.0 already loads missing records through `read_pos_orders` + `missingRecursive` (f12407c2cf31), so the forward-port is a no-op.

opw-6524807

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Forward-Port-Of: odoo/odoo#285912