release MCP CLI

[cdhanna]

Make the Beam MCP CLI public for use.

This release doesn't need to add the MCP to Registries yet, but we need:

• New Docs page about MCP and how to use it and its capabilities
• New Blog post announcing the Beam MCP and which AI we support
• [Optional] CS team notifies our customers about it directly to enforce usage and get feedback about the MCP.

[PedroRauizBeamable]

Waiting for @allister-beamable to provide feedback after its trial-use with Marco. PR for release is ready.