PoolNode and PoolObjectNode each have their own push_one_out(). The previous
commit only reached PoolNode's copy, so ObjectNode-based pipelines — the common
case — still dropped on overflow with lossless enabled.
Verified end to end: a 2300-frame source now reports exactly 2300 frames at
every stage, where it previously delivered 774 to the second node.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>