Merge main, keeping the newer engine pin

main moved MCPP_VERSION from 2026.8.26.1 to 2026.8.26.2 while this branch moved
it to 2026.8.27.1, which is now released. The branch's value is the later of the
two and is what this repository should test against.

⚠️ While the pull request was in a conflicting state it built no `pull_request`
runs at all --- the checks were not failing, they were never created, which
reads as "nothing has run yet" and is indistinguishable from a queue.

Author: speak-agent