dc037b0895
_grammar_bias returned a shared module-level singleton that the loop mutated in place (EOS block + repetition penalty). The penalty thus accumulated across positions within a call and persisted across calls, collapsing output to HOLD/NC until process restart. Clone the bias each step so edits stay local. Add regression tests guarding the invariant. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>