The union-observed-but-variant-never-matched tier was one finding per variant,
so 67 findings described the same fix across 21 unions. Group by marker class
instead: failures and loading markers stay warnings because an unrendered
failure means the user gets no feedback, other markers drop to info.
nuwayze: 146 findings -> 108, and the actionable core is now visible: 14
warnings (2 dormant decisions + 12 missing-feedback groups), down from 49.
Also records a negative result in the README: tiering these by 'variant declares
no fields beyond its base' was tried and rejected, because 67/67 qualified and a
signal true of the whole population cannot discriminate.
