[Enhancement]: Add support for Claude Opus 4.1

[turboncelucionce]

What features would you like to see added?

Add support for Claude Opus 4.1 (claude-opus-4-1-20250805), Anthropic's latest model: https://www.anthropic.com/news/claude-opus-4-1
It has the same feature set and price as Claude 4 Opus, but performs better on certain benchmarks.

More details

The current model picker only lists Claude 4 Opus and prior.

Which components are impacted by your request?

Endpoints

Pictures

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[danny-avila]

You can update the list at any time. I'll make a note to add it to the default list.

https://www.librechat.ai/docs/configuration/pre_configured_ai/anthropic