Feat: Add Nebius Ai Studio Models Support

[Arindam200]

It currently supports multiple LLM providers out of the box. It would be great to add Nebius AI Studio as an additional provider.

Nebius AI Studio offers:

• High-performance LLMs with low-latency streaming
• Tool calling support
• Competitive pricing and scalability
• Compatibility with OpenAI-compatible APIs (making integration straightforward)

This would give developers more flexibility and allow them to try Nebius models alongside other providers already supported.