Unclaim Stock

Put claimed units back on the shelf, in whole or in part.

Without this, changing your mind costs the whole row: delete four units and re-claim three, which spends a second allocation, loses the original claim date, and - if the lot has been restocked since - re-draws at a different FIFO position and a different price. Returning one unused unit should not reprice the three still on the job.

ONE ROW, ONE RESERVATION. The mirrored BOM row names its allocation through mirrored_item_id, so a return releases exactly the reservation that row created. A claim split across three lots is three rows and three returns - which is right: each holds units from a different lot at a different price, and returning "one" has to say which lot it goes back to.