Matches by screen coordinates. This is a special matcher that doesn't
actually match widgets - it's used as a fast path for tapping at
specific screen positions without searching the widget tree.
Overlay widget injected at the root of the app via
FlanBinding.wrapWithDefaultView. Renders inspector interaction
and annotation drawing UI on top of the app content.
Service that implements widget inspector logic: hit testing all elements
at a point, building widget ancestor paths, extracting source locations,
and cycling through overlapping widgets.