CommandProvider
Declares that a plugin contributes operations to the kernel's command table — the discovery seam for Command-as-atom. The canonical successor to `Milpa\Runtime\CommandProviderInterface`: the kernel checks every booted plugin for this interface and merges its {@see operations()} into the list it exposes, from which each surface projector (CLI, MCP, HTTP) materializes its own shape.
CommandProvider::operations()
abstract public function operations(): arrayOperations this plugin contributes.