Merge main, keeping the restructured workflow and main's pin

main moved MCPP_VERSION from 2026.8.24.4 to 2026.8.26.2 while this branch
rewrote the file that holds it, so the two changes met in one line. The pin is
main's, since it names the more recent release and is what an ordinary run of
this repository should test; everything else is this branch's.

⚠️ A pull request in a conflicting state builds no `pull_request` runs at all,
so the checks did not fail --- they were never created. The runs that judged
this branch while it was in that state were dispatched against the branch
rather than raised by the pull request, and this merge is what restores the
ordinary path.

Author: speak-agent

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ on:
 
 env:
   MCPP_SOURCE_REF: ${{ github.event.inputs.mcpp_ref || vars.MCPP_SOURCE_REF }}
-  MCPP_VERSION: 2026.8.24.4
+  MCPP_VERSION: 2026.8.26.2
   XLINGS_VERSION: v2026.8.17.2
   XLINGS_NON_INTERACTIVE: '1'