Need add the latest claude model, example: claude-3-7-sonnet-20250219

**Is your feature request related to a problem? Please describe.**
The project currently lacks support for the latest Claude models, specifically claude-3-7-sonnet-20250219. As AI technology rapidly evolves, newer models typically offer better performance, more accurate responses, and enhanced capabilities, but our project has not yet integrated these latest models, preventing users from benefiting from these improvements.

**Describe the solution you'd like**
Adding claude-3-7-sonnet-20250219 as an option in the model selection list
Implementing proper integration with the Anthropic API to support all parameters for this model
Updating relevant documentation to explain the new model's capabilities and usage
Optimizing the interface to support any special features the new model might offer (such as higher token limits)

**Describe alternatives you've considered**
Continuing to use older Claude models, but this would miss out on performance and feature improvements
Using similar models from other providers, but the Claude series has unique advantages for certain tasks
Creating custom adapters as a temporary solution, but this requires extra maintenance and may be unstable
**Additional context**
claude-3-7-sonnet-20250219 is one of the latest models released by Anthropic, featuring stronger reasoning capabilities and better instruction following
Many competing products have already integrated this model
Several users in the community have expressed interest in this feature in discussions
According to Anthropic's documentation, integrating this model requires minimal API adjustments

Look for the model definitions and API client in the codebase, likely in a module like `langchain_rust::clients::anthropic`. Find where existing Claude models are listed and add the new model identifier. Check the Anthropic API documentation for any required parameter changes. Test the integration by running existing tests for the Anthropic client.

由索引模型根据 Issue 内容生成。