- Clamp the summary request's max_tokens to the model's output limit so a
large STRIX_CONTEXT_SUMMARY_TOKENS can't get the request rejected (which
left the overflowing session uncompacted). Applied consistently to the
input-budget reservation and the request itself.
- Replace the tokenizer-unavailable fallback with the UTF-8 byte length, a
guaranteed upper bound on tokens for byte-level BPE, so budget checks can
never under-count dense history.