OBLS-940 Refresh putaway candidates and fix putaway location entry - #443

Putaway Candidates only fetched in componentDidMount, so returning from
a completed putaway showed a stale list, and the filtered rows were held
in state that a refresh never recomputed. Converted the screen to a
function component so it refetches on focus and derives the visible list
from the fetched data, which removes both stale paths. The unreachable
"already in a pending putaway" alert is gone, since the READY filter
already excludes every row that has an id.

Putaway Item Detail could not complete a putaway at all. The scan field
was rendered with editable false and the screen had no scan listener, so
scannedPutawayLocation stayed empty and validatePutawayItem rejected
every submission. It now uses ScannerInput for hardware scans, manual
typing and the destination bin search, and Confirm is gated on a
location being present instead of failing server side.

The root cause of the dead search and Confirm buttons was the bare
ScrollView, which defaults keyboardShouldPersistTaps to never, so the
first tap was consumed dismissing the keyboard while the input held
focus. Every sibling screen sets this prop; this one did not, and the
previous non editable field hid it.

Completing a putaway now drops the row immediately. The backend defers
the product availability refresh, so the candidates response still
reports the old quantity for a while after the transfer. An override
keyed on bin, lot and product records the expected remaining quantity
and is discarded once the server reports a quantity at or below it.