Add canUseTool permission support to Python SDK

[szwang]

This commit completes the canUseTool permission functionality implementation in the Python SDK to match the TypeScript SDK behavior:

Key Changes:

1. Transport Layer Enhancement (subprocess_cli.py):

   • Added --can-use-tool CLI flag when canUseTool callback is provided
   • Ensures the CLI process knows to enable permission callback mode

2. Example Implementation (can_use_tool_example.py):

   • Comprehensive example showing how to use canUseTool callbacks
   • Demonstrates security policies, input modification, and denial patterns
   • Shows integration with ClaudeSDKClient in streaming mode

Features Already Implemented:

• Type Definitions: CanUseTool, PermissionResult*, ToolPermissionContext in types.py
• Client Integration: Full canUseTool support in ClaudeSDKClient with proper validation
• Query Support: Both query() function and ClaudeSDKClient handle canUseTool callbacks
• Control Protocol: Complete bidirectional permission request/response handling
• Input Validation: Ensures streaming mode is required, mutual exclusion with permission_prompt_tool_name
• Comprehensive Tests: Full test coverage in test_tool_callbacks.py

The implementation follows the TypeScript SDK's architecture exactly, providing:

• Tool permission interception before execution
• Input modification capabilities
• Permission updates and suggestions
• Proper error handling and validation

🤖 Generated with Claude Code