verified 251,408 (ambiguous dropped 37,615) -> 250,842 after dedup
  train                    196,297
  eval_held                  6,061
  eval_unseen_phrasing       8,723
  eval_unseen_dialect       39,761
  eval_hard                    728

held-out families in train: none
held-out variety in train : none

--- audit ---
class mix: {'safe': '17.8%', 'safe_sensitive': '11.8%', 'privacy_pii': '8.2%', 'specialized_advice': '8.0%', 'self_harm': '7.9%', 'prompt_injection': '7.6%', 'jailbreak': '7.5%', 'sexual_content': '7.4%', 'hate_harassment': '7.0%', 'violent_weapons': '6.0%', 'misinformation': '5.8%', 'nonviolent_crime': '5.0%'}
length shortcut: majority 0.1785 | best threshold 0.1798 | leak +0.0013
variety mix: {'عربي مختلط بالإنجليزية': '17.1%', 'اللهجة المصرية': '16.8%', 'اللهجة الشامية': '16.7%', 'اللهجة الخليجية': '16.7%', 'اللهجة المغاربية': '16.4%', 'العربية الفصحى': '16.3%'}
TOTAL: 250,842