Remove defaults: user picks provider, model, and key. Expanded model lists for all 5 providers

Add multi-provider LLM inference (OpenAI/Claude/Gemini/HF/Grok), conversation dialogue in logs, seller tells in system prompt

Add spectator mode, sell mode, fix replay/leaderboard errors, push-ready for HF

Add seller personalities, poker tells, WebSocket, multi-buyer arena, leaderboard, counterfactual analysis, and React UI