handle_batch_message

handle_batch_message(msg, progress_bar, batch_task_ids, lock)

Process a batch-level progress message in the unified progress bar.

Batch rows are created dynamically per batch_id so that split sub-batches (e.g. expval vs shots) each get their own status line. The conditional column wrappers keep the bar/M-of-N/elapsed cells empty for batch rows; the indicator/text/spinner/status columns render normally.

Program-row coloring works by reading each task’s program_key field — no parallel program_key → TaskID index needed. Reading progress_bar._tasks mirrors the same pattern used elsewhere in the listener.