CaptiOCR v0.16.1

v0.16.1: End-of-stream flush for trailing captured frames

Add end-of-stream flush logic to the fidelity pipeline so that
trailing frames still in the buffer at the end of capture are
emitted rather than silently dropped. The flush candidate goes
through the same no-downgrade, dedup, overlap, and sentence-split
steps (4-7) as regular consensus blocks, ensuring consistent
output quality.