Auto Unreserve

When a transfer cannot be reserved because the needed products are already reserved by other transfers, this module lets a user force the reservation instead of manually unreserving those other documents first.

On the transfer form, next to the standard reserve button, a "Force reservation" button appears for members of the new "Force availability on pickings" group (administrators are added by default). The button is only shown when the transfer is in a state where availability checking makes sense.

Pressing it looks for other transfers from the same source location that hold reservations of the same products, starting with the oldest updated ones, and releases just enough of their reserved quantities to cover what the current transfer still needs. It then tries to reserve the current transfer.

Both sides are traced in the chatter: the current transfer logs which transfers were unreserved for it, and each affected transfer logs that it was unreserved to help another one.

A system setting, "allow partial" (off by default), controls what happens when there is not enough reserved stock elsewhere: if off, the action is blocked with an error naming the product and the missing quantity; if on, the action proceeds with whatever could be freed. The module only touches stock.picking and its moves.