- Define clean API with complete() method and callbacks for streaming
- Add comprehensive type system for messages, tools, and usage
- Implement AnthropicAI provider with full feature support:
- Thinking/reasoning with signatures
- Tool calling with parallel execution
- Streaming via callbacks (onText, onThinking)
- Proper error handling and stop reasons
- Cache tracking for input/output tokens
- Add working test/example demonstrating tool execution flow
- Support for system prompts, temperature, max tokens
- Proper message role types: user, assistant, toolResult
