Adds NearAiProvider that uses the NEAR AI unified API at
api.near.ai/v1/responses with session token authentication.
This provides access to multiple models (OpenAI, Anthropic, etc.)
through a single endpoint with user auth and usage tracking.
- Add src/llm/nearai.rs with complete provider implementation
- Add NearAiConfig to config.rs with session_token, model, base_url
- Add NearAi variant to LlmProvider enum (accepts nearai/near-ai/near_ai)
- Change default provider from OpenAi to NearAi
- Update .env.example with NEAR AI configuration
- Update CLAUDE.md documentation
Co-Authored-By: Claude Opus 4.5 <[email protected]>
