The Macro document UUID referenced by a Script action.
Variables passed to the macro body (Foundry spreads these as
{ speaker, actor, token, ...scope }).
The macro's result, or undefined if the UUID does not resolve to a
Macro (a non-Macro or missing document is ignored, not executed).
This is the sanctioned way to run author-supplied ("homebrew") behavior: the
command lives in a permission-gated Macro document, never in system data,
and Macro#execute enforces canUserExecute (ownership and the
MACRO_SCRIPT user permission) before running. No code is ever compiled from
serialized data. See sohl.entity.action.SohlAction and the Security Model doc.
Resolve a Foundry Macro by UUID and run it via
Macro#execute.