The five bowl fixtures compare to the zone's own normal, so nothing pinned
the shared well's depth or radius to the bowl (a depth-scaled fixture
mutant survived). TheWellFixtureReproducesTheFormerBowl checks heights
against the bowl's own definition. This commit's test has not run yet.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>