The free-form scanner attempted raw_decode at every '{', including braces
inside an already-decoded object, so 'return the last decodable object'
(deliberate: chain-of-thought models emit draft JSON before the final answer)
actually returned the innermost/trailing nested fragment — e.g.
{"next_prompt": ..., "style": {"mood": "noir"}} parsed to {"mood": "noir"}
and enhancement fell back, failing steering requests.
Scan with a position cursor instead: skip past the consumed span of every
successfully decoded object, and skip malformed/truncated spans wholesale via
a balanced-brace scan so their nested fragments can't displace an earlier
complete object. Regression tests cover nested values, sequential drafts,
truncated tails, and the nested rollout shape.
SolitaryThinker
deb51f1dcc