Documented MAC MCP runtime surface

Property	Value
description	Updated the MAC MCP product docs for the local stdio runtime and read-only inventory tools.
version	0.66.0
type	Update
related	MAC MCP

• Documented the local stdio runtime surface for MAC MCP.
• Listed the first read-only tools and resources.
• Recorded the local-only, read-only, no-auth scope for the first runtime wave.