Point the range picker at the shared segmented control

RangePicker carried a byte-for-byte copy of ui/segmented.tsx's markup; it
now renders that component instead.

The dashboard's own segmented widget stays where it is: it is not a copy
but a look-aware control, drawn per look in
Dashboard/ui/{fluksio,glass,material}/Controls.tsx over the shared
useSegmented behaviour. Note that in segmented.tsx in place of the stale
size-prop plan.

frontend/src/components/Common/RangePicker.tsx

@@ -1,8 +1,4 @@
-// The segmented shape's thumb transition lives beside the dashboard's own
-// widgets, and CSS is chunked per entry — so the rule is pulled in wherever
-// this picker is used, or the two copies of one shape would move differently.
-import "@/components/Dashboard/dashboard.css"
-import { cn } from "@/lib/utils"
+import { Segmented } from "@/components/ui/segmented"
 
 /**
  * A window of history, and everything a query needs to ask for it.
@@ -39,12 +35,7 @@ export const DEFAULT_RANGE = RANGES[2]
 export const rangeStart = (range: Range) =>
   new Date(Date.now() - range.hours * 3600_000).toISOString()
 
-/**
- * The window a screen is showing, as presets.
- *
- * The one segmented shape: a single border pill, transparent segments,
- * bg-accent on the selected one (root DESIGN-GUIDELINES.md).
- */
+/** The window a screen is showing, as presets. */
 export function RangePicker({
   value,
   onChange,
@@ -52,47 +43,20 @@ export function RangePicker({
   value: Range
   onChange: (range: Range) => void
 }) {
-  const chosen = RANGES.findIndex((range) => range.hours === value.hours)
   return (
-    // A `fieldset` carries `min-inline-size: min-content` from the UA sheet,
-    // which no width utility overrides. Equal tracks and no gap put the
-    // sliding thumb at its share of the padded box without measuring — a grid
-    // rather than a flex row because `flex-1` under `w-fit` sizes the segments
-    // to a share of the widest label instead of to the label itself.
-    <fieldset
-      data-testid="range-picker"
-      className="relative grid w-fit min-w-0 items-center rounded-full border border-border p-1"
-      style={{
-        gridTemplateColumns: `repeat(${RANGES.length}, minmax(0, 1fr))`,
-      }}
-    >
-      <legend className="sr-only">Time range</legend>
-      {chosen >= 0 ? (
-        <span
-          aria-hidden
-          className="widget-segment-thumb pointer-events-none absolute inset-y-1 rounded-full bg-accent"
-          style={{
-            left: `calc(0.25rem + ${chosen} * (100% - 0.5rem) / ${RANGES.length})`,
-            width: `calc((100% - 0.5rem) / ${RANGES.length})`,
-          }}
-        />
-      ) : null}
-      {RANGES.map((range, index) => (
-        <button
-          key={range.label}
-          type="button"
-          aria-pressed={index === chosen}
-          onClick={() => onChange(range)}
-          className={cn(
-            "relative z-10 min-w-0 rounded-full px-2.5 py-1 text-xs transition-colors",
-            index === chosen
-              ? "text-accent-foreground"
-              : "text-muted-foreground hover:bg-accent/50",
-          )}
-        >
-          {range.label}
-        </button>
-      ))}
-    </fieldset>
+    <Segmented
+      testId="range-picker"
+      label="Time range"
+      value={String(value.hours)}
+      options={RANGES.map(
+        (range) => [String(range.hours), range.label] as const,
+      )}
+      onChange={(hours) =>
+        onChange(
+          RANGES.find((range) => String(range.hours) === hours) ??
+            DEFAULT_RANGE,
+        )
+      }
+    />
   )
 }

frontend/src/components/ui/segmented.tsx

@@ -1,6 +1,5 @@
 // The thumb's transition lives beside the dashboard's own widgets, and CSS is
-// chunked per entry — so the rule is pulled in wherever this control is used,
-// or two copies of one shape would move differently.
+// chunked per entry — so the rule is pulled in wherever this control is used.
 import "@/components/Dashboard/dashboard.css"
 import { cn } from "@/lib/utils"
 
@@ -9,9 +8,11 @@ import { cn } from "@/lib/utils"
  * transparent segments, and `bg-accent` held by a thumb that slides rather than
  * a fill that jumps from cell to cell (root DESIGN-GUIDELINES.md).
  *
- * ponytail: sized for editor chrome — `w-fit`, `text-xs`, a mouse-sized target.
- * The widget-side copy in `Dashboard/widgets.tsx` is a full-width pill with a
- * 44px touch target, so pointing that one here needs a size prop first.
+ * App-side chrome only — `w-fit`, `text-xs`, a mouse-sized target. The
+ * dashboard's own segmented widget is not this component and never will be:
+ * it is drawn per look by `Dashboard/ui/{fluksio,glass,material}/Controls.tsx`
+ * over the shared `useSegmented` behaviour, as a full-width pill with a 44px
+ * touch target. Folding the two together would flatten the three looks.
  */
 export function Segmented({
   value,