Draw the panel as a panel

Five things a wall panel showed that a wall panel should not.

**A tile's body no longer clips.** It scrolled, and a box that scrolls
also cuts whatever crosses its edge — which took the glow off a lit
button at exactly the width where the button filled its tile, and off a
gauge's arc at exactly the height where the dial filled its own. Only
what is written or listed asks for a scroller now; everything else is a
picture drawn to fit, and what overflows is left to the frame, which
clips at the tile's edge where a shadow has already faded out. The
slider's phantom scrollbar goes with it.

**The selector is a selector.** Named for what it does rather than what
it is, and the choice it is holding is held in the dashboard's own
primary — a pill that slides between the options rather than a grey one
that had to be looked for. The stored type is untouched, so no document
changes meaning.

**The arrangement is held off the panel's edges**, by the same distance
it holds between two widgets. The ground is not held off with it: a
background covers the whole panel, and only what is arranged on it has
a margin. No stored panel loses a row to it.

**The rail is drawn on the panel.** It was chrome bolted to the edge of
the screen beside the canvas — in the app's own design rather than the
dashboard's, and on a scaled canvas not even lined up with it. It now
takes a column out of the canvas the way the margin does, scaled with
it and wearing its look. Which cell each widget sits in is unchanged;
only how big a cell is.

Two of these were the same mistake twice: an unlayered rule stating
`position` for everything wearing a class — `.gl-surface` on a rail
placed by a utility, and a blanket lift over every child of a pressable
on a pill placed by `layoutId`. Both now say it one element at a time.

frontend/src/components/Dashboard/ui/glass/Controls.tsx

@@ -51,7 +51,7 @@ export function Button({
       onClick={onClick}
     >
       <span className="gl-glow" aria-hidden />
-      <span className="min-w-0 truncate">{children}</span>
+      <span className="gl-lift min-w-0 truncate">{children}</span>
     </motion.button>
   )
 }
@@ -181,11 +181,14 @@ export function Select({
         className="gl-field gl-pressable justify-between"
       >
         <span className="gl-glow" aria-hidden />
-        <span className="min-w-0 truncate">
+        <span className="gl-lift min-w-0 truncate">
           <SelectPrimitive.Value placeholder="Choose" />
         </span>
         <SelectPrimitive.Icon asChild>
-          <ChevronDown className="size-4 shrink-0 opacity-60" aria-hidden />
+          <ChevronDown
+            className="gl-lift size-4 shrink-0 opacity-60"
+            aria-hidden
+          />
         </SelectPrimitive.Icon>
       </SelectPrimitive.Trigger>
       <SelectPrimitive.Portal>