Fix all provider names to match OpenClaw system (zai, moonshot, mistral, xai, opencode, etc.)

Fix Anthropic model names: use OpenClaw format (hyphens) not OpenRouter format (dots)

Fix provider names to match OpenRouter API (z-ai, mistralai, moonshotai, deepseek, meta-llama, etc.)

Add OpenRouter support + 15+ popular models (Qwen, Grok, MiMo, Seed, Nemotron, GLM, Mercury, etc.)

Add support for multiple LLM providers (Zhipu, Moonshot, MiniMax, Mistral, Cohere, Groq, etc.)

Add .env.example with complete configuration reference