Add MiniMax (MiniMax-M2.5) and Zhipu as new OpenAI-compatible LLM
providers with factory routing, API endpoint config, and env vars.
Also add CLAUDE.md for Claude Code guidance.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Add StatsCallbackHandler for tracking LLM calls, tool calls, and tokens
- Integrate callbacks into TradingAgentsGraph and all LLM clients
- Dynamic agent/report counts based on selected analysts
- Fix report completion counting (tied to agent completion)