feat: add Sunra AI official MCP server to README

[banyudu]

Description

Add Sunra.ai official mcp server. Sunra.ai is a generative media platform built for developers, providing high-performance AI model inference capabilities. It specializes in running diffusion models through production-ready APIs and interactive UI playgrounds.

Server Details

• Server: N/A. New official mcp server
• Changes to: N/A

Motivation and Context

Add Sunra.ai mcp server to the official mcp server list.

How Has This Been Tested?

We tested the MCP server using the cursor agent. Tools such as 'list-models', 'search-models', 'model-schema', 'status', and 'result' have all been evaluated.

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

Additional context

N/A

[olaservo]

Thanks for your contribution to the servers list. This has been merged in this combined PR: #2374

This is a new process we're trying out, so if you see any issues feel free to re-open the PR and tag me.