Ensure accommodation products are linked to the correct reservation when added from an open bill

Description:

When working from an already opened bill in Mews, adding an accommodation product via "Add product" → "Accommodation" does not automatically link the product to the reservation associated with that bill.

Instead, the system selects a different reservation (for example a future reservation or a previously cancelled one), which does not match the current billing context.

This behavior is not intuitive, as the user is actively working within a specific bill that is already tied to a reservation.

Suggested improvement:

When adding an accommodation product from within an open bill, Mews should:

Automatically link the product to the reservation associated with that bill, or
Clearly prompt the user to select a reservation, with the correct one preselected