Two kinds of drift only surface when a user hits them. The compatibility
catalog falls behind what the provider publishes, so new installs land on
a version Roblox has since retired; and the preferred supported profile
loses its pinned bootstrap source, so the pinned bootstrap path cannot
produce the version the updater falls back to.
Add a checker that reports both, and run the existing script unit tests in
CI, where they were never executed.
Run against this tree the checker already reports real drift: the
preferred profile 2.727.1199 has no pinned bootstrap source. Pinning one
means downloading and hashing the archive, and a newer profile also needs
a graphics canary on real hardware, so this reports the condition rather
than pretending to fix it.
The checker stays a plain script that anyone can run on demand; no
scheduled workflow is added.
