Measured after the DELTA fix: 53 engine outputs for 52 rows, but the client
still received everything at once because each per-step payload is the newest
row only and the row alignment treated it as a cumulative snapshot (one yield
at the first row, one at the end). accumulate_codec_rows folds delta rows and
the final consolidated matrix into one growing matrix; unit test drives the
generator with per-step deltas and asserts one yield per step.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
The speech path forced FINAL_ONLY for Qwen3-TTS deployments without async
chunks, so a talker-only server emitted one engine output per request and all
codec frames arrived at once (measured: 1 engine output per request, first
codes at output #1). A talker-only stage (final_output + latent) now keeps
DELTA outputs so codec frames stream per step.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
