Hover was per-sensor state that only changed when the walk reached that
sensor, so ending it depended on the walk, which consumption cuts short.
`CursorSenses` now keeps the set of widgets the cursor was inside, in a
new `Event::Global` slot for state a whole event type owns rather than
each widget -- which is also where the input restructure keeps its pointer
capture.
The walk visits only widgets the cursor is inside and stops at the layer
that consumes, as before. Whoever was in the set and is not now has been
left or covered, and gets its `HoverEnd` afterwards, however early the
walk stopped.
Two things fall out. `SensorState` is gone: whether a hover is starting,
on or ending is the difference between the two sets. And the consumption
line loses its `&& in_shape`, since being inside is now the reason the
widget is looked at rather than something to test again.
Nine tests, five of which fail on `main`. `hover_starts_and_ends_once_each`
pins the lifecycle, and `covering_a_widget_ends_its_hover` now returns the
cursor so an uncovered widget hovers again.
`Event::consumes` says whether having run uses up what triggered it,
defaulting to no. `run_fn` already calls `should_run` per registration,
so it ors that across everything that ran and hands it back through
`run_event`. `CursorSenses` answers it with the sense it matched: a press
or a scroll is used up, hovering is not.
That drops `TypeEventManager::registered` and the second pass over a
widget's senses -- the match that decides consumption is now the same one
that decides whether the handler runs.
A cursor that is only resting still stops at the layer it is over, which
`run_event` cannot report because nothing need answer for it to be true.
It must not stop at a widget it has merely left, though, or ending a hover
above blocks the hover below: `leaving_a_widget_does_not_block_the_layer_below`
is that case, and it fails on `main` too.
iris