`action::exercise` read `invocation.affordance` and looked the entry up
itself, with the grant check standing beside it in each caller. Pass 5 adds
a third caller, so the check becomes the type: `require_granted` now returns
a `GrantedAffordance` carrying the verified id and its catalog entry, and
`exercise` takes that instead of the raw id. Nothing in the pipeline reads
`invocation.affordance`, and no caller can reach it ungated.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>