Let a widget's glow fade out instead of stopping at the tile's edge

`overflow: hidden` on the frame and its body cut a control's 22px
`--gl-glow` dead at the clip edge, and the gauge's own `<svg>` cut its
drop-shadow at the viewBox — the arc's top sits ~3.5 units from it.
`overflow: clip` with a margin wide enough for the blur (1.5rem on the
body, which already sits 1rem inside the frame; 0.5rem is all that leaves
the tile, which is the gutter).

That means the body no longer scrolls by default. `.dui-frame-scroll` was
already wired through from `scrolls()` into every look's Surfaces with no
CSS rule behind it, so the class is what opts markdown, agenda and
notification back into a real scroller.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KYM38KSb4V4v2T71eifnZv

frontend/src/components/Dashboard/ui/glass/glass.css

@@ -152,7 +152,11 @@
 
 .gl-pressable {
   position: relative;
-  overflow: hidden;
+  /* `clip` rather than `hidden`: the press ripple below is inset 0 and rounds
+     with the surface regardless, but a segment's `--gl-glow` thumb sits inside
+     this box too and needs room to fade rather than being cut off at it. */
+  overflow: clip;
+  overflow-clip-margin: 1.5rem;
   isolation: isolate;
 }