Adds Needle as an MCP client to docs/clients.mdx:

• Added Needle to the feature matrix (Resources/Prompts/Tools/Discovery ✅; Sampling ❌; Roots ❌; Elicitation ❓)
• Added [Needle]: https://needle.app link reference
• Added a “Needle” client details section with key features and docs links

Motivation and Context

Needle web works as an MCP client, allowing users to connect remote MCP servers quickly and use their tools in Needle collections. Including it helps users discover a web-based MCP client that supports secure OAuth flows, server previews, and tool invocation.

• Getting Started: https://docs.needle.app/docs/guides/hello-needle/getting-started/
• Needle MCP Client: https://docs.needle.app/docs/guides/mcp/getting-started/

How Has This Been Tested?

• Verified MDX renders correctly in the docs file
• Lint checks pass for docs/clients.mdx

Breaking Changes

None

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 Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

• Needle matrix row reflects current support: Resources/Prompts/Tools/Discovery ✅; Sampling ❌; Roots ❌; Elicitation ❓
• Client details include: instant MCP integration via Connectors, built-in RAG, secure OAuth authorization, smart server previews, and tool invocation within Needle