feat(frontend): skeleton loading states, empty-state glow, light-mode polish

- Add shared skeleton building blocks (SkeletonHero, SkeletonMetricRow,
  SkeletonPanel, SkeletonRows) and wire them into every view's initial
  loading branch, replacing bare spinners for a cohesive shimmering shell.
- Polish EmptyState with a glow-ring icon chip instead of a flat icon.
- Harden .light theme: color-scheme, tuned scrollbar + selection for pale
  canvas. Dark/light theme toggle (next-themes) already persisted in TopBar.

services/frontend/src/app/(dashboard)/dashboard/view.tsx

@@ -13,7 +13,13 @@ import { useEffect } from "react";
 import { useAmbient } from "@/components/ambient/ambient-context";
 import { AreaActivity, RadialGauge } from "@/components/charts";
 import { GlassPanel } from "@/components/primitives";
-import { ErrorState, LoadingState } from "@/components/shared";
+import {
+  ErrorState,
+  LoadingState,
+  SkeletonHero,
+  SkeletonMetricRow,
+  SkeletonPanel,
+} from "@/components/shared";
 import { MetricTile, SectionHeader } from "@/components/shared/section";
 import {
   useActivity,
@@ -59,7 +65,18 @@ export function DashboardView({
   }, [stats, ambient]);
 
   if (error && !stats) return <ErrorState error={error} />;
-  if (!stats && isLoading) return <LoadingState label="Reading grid" />;
+  if (!stats && isLoading)
+    return (
+      <div className="space-y-5">
+        <SkeletonHero />
+        <SkeletonMetricRow cols={4} />
+        <SkeletonPanel rows={5} />
+        <div className="grid gap-5 lg:grid-cols-5">
+          <SkeletonPanel className="lg:col-span-3" rows={4} />
+          <SkeletonPanel className="lg:col-span-2" rows={4} />
+        </div>
+      </div>
+    );
   if (!stats) return <ErrorState error={error ?? new Error("No data")} />;
 
   const s = stats;