fix(chart-overlay-controls): bump cog to 44x44 tap target

The settings-cog trigger was 28x28 CSS px (h-7 w-7), below the
WCAG 2.1 AA 44x44 minimum. Sat in the same flex row as the 44 px
range tabs, so a Pixel-5 thumb missed the cog more reliably than
the surrounding tabs. Switch to min-h-11 min-w-11; icon stays at
h-3.5 w-3.5 so visual rhythm doesn't bloat.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/charts/chart-overlay-controls.tsx

@@ -92,7 +92,7 @@ export function ChartOverlayControls({
           type="button"
           variant="ghost"
           size="sm"
-          className={`text-muted-foreground hover:text-foreground h-7 w-7 px-0 ${triggerClassName ?? ""}`.trim()}
+          className={`text-muted-foreground hover:text-foreground min-h-11 min-w-11 px-0 ${triggerClassName ?? ""}`.trim()}
           aria-label={t("chart.overlay.controls.tooltip.openSettings")}
           data-slot="chart-overlay-controls-trigger"
         >