ElyShell now hosts a translucency_slider: Entity<SliderState> bound to
0..=100 step 1, defaulting to DEFAULT_TRANSLUCENCY_PCT. A subscription
on SliderEvent::Change writes the rounded value into the core via
set_translucency_pct, so dragging the thumb mutates the persisted
appearance setting in real time.
The appearance form swaps the static track-and-thumb visual for the
gpui_component Slider (160 wide) plus a live percentage readout. The
three preset chips move below the row as fast-set buttons that go
through a new set_translucency_pct_from_preset helper which writes
both core and the SliderState so the thumb tracks the chip choice.
reset_appearance now resets the slider to DEFAULT_TRANSLUCENCY_PCT
alongside resetting the core, keeping every UI source of truth in
lock-step.
ZacharyZhang-NY
797560d71c