Surya asks every request for logprobs and averages exp(logprob) over the
generated tokens to score each line. coderai accepted the parameter, never
sent it, and hardcoded `logprobs: None` in every response builder.

Surya's fallback is what makes that expensive: with no logprobs it does not
report "unknown", it reports a literal 1.0 (recognition/__init__.py:248, :302,
layout/__init__.py:97). Every line of every page comes back perfectly
confident, the guesses included, and nothing downstream can tell which
judicial document needs a human to look at it.

So the round trip is wired where it can exist: the proxy backends (vLLM,
RunPod) forward `logprobs`/`top_logprobs` and hand back what the server
measured, buffered and streamed, accumulating the streamed pieces into one
response-shaped object. The manager asks the backend's signature rather than
negotiating by TypeError, which would have called it twice for a kwarg it
never had. A request that did not ask is sent exactly as before, and a
backend that cannot answer still returns null.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PxYHWbCAjjjD7A1rhFKtaW