include "normalize";
($stock[0].warehouses
 | [.[].bins[]]
 | group_by(.sku)
 | map({key: .[0].sku, value: (map(.onHand - .reserved) | add)})
 | from_entries) as $available
| [.accounts[] | account_rows]
| group_by(.sku)
| map(
    .[0].sku as $sku
    | (map(.netQty) | add) as $demand
    | {sku: $sku, demand: $demand, available: $available[$sku],
       shortage: (if $available | has($sku)
                  then ([$demand - $available[$sku], 0] | max)
                  else null end)})