[throwaway probe A — fenced] closing-keyword reading for #8476 step 1 #8520

Throwaway target for the #8476 step-1 live reading. This issue is the FENCED-BLOCK arm: a throwaway PR will carry a closing keyword bound to this number inside a fenced code block. If a closing link appears here, stripMarkdownCode's fence rule in scripts/pm/check-half-states.mjs is a false negative and must be revised.

Closed immediately after the reading. No work is requested here.