Previously --resume re-queried every gradient in every row, overwriting
existing values — an interrupted run could not be resumed cheaply.
- bicorder_query.py: add --resume flag; skip gradients whose cells already
have values, and report how many were skipped
- bicorder_batch.py: pass --resume through to query; skip fully-complete
rows before invoking the query script; report partial rows
- bicorder_batch.py: import row/config helpers from bicorder_query instead
of calling undefined names (would have crashed on --resume)
