A routed request arrives as `agy/...` or `antigravity/...`, and cleanModelName
strips that prefix before the ceiling is resolved. Neither function mentions
the other, so a change to the stripping would send every prefixed request to
the fallback with nothing failing: the capability lookup returns null for a
prefixed id, and null is exactly what the fallback is for.
Deleting the strip turns this test red along with five existing ones, which is
the coupling made visible.