v0.8.5 - ZeroClaw upstream response

0.8.5 - 2026-02-20

Added (ZeroClaw upstream response)

• ChatRequestBuilder::model(): Override model per request for single-client multi-model usage
• ChatRequestBuilder::tools_json(): Set tools from raw Vec<serde_json::Value> for JSON Schema integration
• Error::is_retryable(), Error::retry_after(), Error::error_code(): Convenience methods for error handling
• AiClient::metrics(): Returns ClientMetrics snapshot (total_requests, successful_requests, total_tokens)
• ClientMetrics: New type for cumulative client metrics

Changed

• Documentation: execute_stream_with_cancel and CancelHandle Rustdoc with examples
• Documentation: Arc sharing pattern in README and AiClientBuilder (replaces Clone for ToS compliance)
• Fallback behavior: Model override from ChatRequestBuilder::model() preserved for primary client; fallback clients use their own model_id