phi4-mini 400s at ~13k tokens; gemma4-26b is correct to 90,000 chars and
silently loses the HEAD at 120,000 (no error, no truncation flag). The
end-needle test alone passed at 120k -- only a head-needle exposed it.
Records the default-model trap and the iguana contention hazard.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
