Live LLM arena leaderboards with rank deltas, context length and $/M-token pricing

Six boards: text, code, agent, document, vision, search. Score is arena Elo; votes are vote counts — except the agent board (score = net-improvement %, votes = sessions; see each board's note). delta is rank movement vs the previous captured snapshot; null when no baseline exists. context/priceIn/priceOut come from the OpenRouter public catalog; null when the arena name has no catalog match.