This pull request adds AgentOps integration to the ReagClient class in the Python client. The changes include:

1. Import AgentOps and check for its availability.
2. Add optional parameters for AgentOps configuration in the ReagClient constructor.
3. Initialize AgentOps in the constructor if the API key is provided.
4. Update the class docstring to include information about AgentOps integration.

These changes allow users to easily enable AgentOps monitoring for their ReAG queries by providing an AgentOps API key and optional configuration when initializing the ReagClient.

No additional dependencies are installed, as AgentOps is imported conditionally.