55 element groups across text, buttons, choice, input, slider, layout, status,
overlays, gallery and the wheel picker. Each lands in a registry-driven
catalogue that shows every variant in both themes, so an element that fails to
register is visibly absent rather than quietly missing.
rule_content_is_data iterates the REGISTRY, not a list: a new element is
attacked with markup the moment it calls define(), and one without a demo fails
the suite. That is announcement-not-enumeration applied to the tests.
Fixes found while building: checkbox silently ignored its label (inverted
logic left it with aria-label=toggle), the overlay root set z-index 0 and so
became a stacking context that trapped every overlay it was built to free, and
raising a window left its peers' z stale because z is derived from position --
claim() now notifies a rung when a peer moves.
The wheel highlights the actual sector rather than a box around the label: the
lit shape is the region that picks the item, which is what makes it aimable.
