Set Inventory Count

"Set count" on the Inventory page: the person enters the number on the shelf and Roost writes the difference as a count transaction, recording who and when (Frederick, 2026-09-24: Samuel "can enter the total number in stock"). Gated on fulfillment:inventory:write, the same grant as every other stock change on that page -- the Fulfillment technician role holds it in production (checked read-only 2026-09-24).