Esperanto

- Added Python 3.9 support

Documentation Updates

- Updated installation instructions in README files to reflect new dependency structure
- Added documentation for new extras:
- 'langchain': For LangChain integration
- 'all': For all providers without LangChain
- 'all_with_langchain': For all providers including LangChain

This release improves documentation to help users understand the new dependency structure introduced in v0.9.0.

- Fix dependency conflicts by centralizing langchain dependencies and adding version constraints

Bug Fixes

* Fixed incorrect parameters being passed to LangChain client for reasoning models (o1, o3), which was causing integration failures.

What's New

- Added client properties to access raw provider clients
- New property for synchronous client access
- New property for asynchronous client access
- Available across all LLM providers (OpenAI, Anthropic, Groq, etc.)
- Enables direct access to provider-specific functionality

- Added comprehensive test coverage for client properties
- Tests for each provider's client interface
- Tests for base class client properties
- Verification of async client methods