feat(ui): email dashboard UX refactor (PHASES 1/3/4) (#44)

frontend/src/pages/Dashboard.jsx

@@ -6,8 +6,9 @@ import { AnalyticsApi, LayoutApi, ExportApi, SyncApi } from '../api/client.js';
 import SyncSplash from '../components/SyncSplash.jsx';
 import {
   HealthWidget, StatCard, TopSendersWidget, VolumeWidget,
-  CategoryHeatmapWidget, AttachmentsWidget, StorageWidget
+  CategoryBreakdownWidget, AttachmentsWidget, StorageWidget
 } from '../components/widgets.jsx';
+import { Skeleton } from '../components/ui/skeleton.jsx';
 
 // Default grid geometry; overridden by the user's saved layout.
 const DEFAULT_LAYOUT = [
@@ -17,12 +18,23 @@ const DEFAULT_LAYOUT = [
   { i: 'storage', x: 7, y: 0, w: 2, h: 2 },
   { i: 'top-senders', x: 3, y: 2, w: 3, h: 5 },
   { i: 'volume', x: 6, y: 2, w: 6, h: 4 },
-  { i: 'category-heatmap', x: 0, y: 5, w: 6, h: 5 },
+  { i: 'category-breakdown', x: 0, y: 5, w: 6, h: 5 },
   { i: 'attachments', x: 6, y: 6, w: 4, h: 4 },
 ];
 
 const ALL_WIDGETS = DEFAULT_LAYOUT.map((l) => l.i);
 
+function WidgetSkeleton() {
+  return (
+    <div className="widget">
+      <Skeleton className="mb-3 h-4 w-1/3" />
+      <Skeleton className="mb-2 h-3 w-full" />
+      <Skeleton className="mb-2 h-3 w-5/6" />
+      <Skeleton className="h-3 w-2/3" />
+    </div>
+  );
+}
+
 export default function Dashboard() {
   const [data, setData] = useState(null);
   const [layout, setLayout] = useState(DEFAULT_LAYOUT);
@@ -87,15 +99,18 @@ export default function Dashboard() {
   const visibleLayout = useMemo(() => layout.filter((l) => !hidden.includes(l.i)), [layout, hidden]);
 
   const render = (key) => {
+    // category-breakdown self-fetches, so it renders regardless of dashboard load state.
+    if (key === 'category-breakdown') return <CategoryBreakdownWidget />;
+    // While the dashboard payload loads, show a skeleton placeholder per widget.
+    if (!data) return <WidgetSkeleton />;
     switch (key) {
-      case 'inbox-health': return <HealthWidget health={data?.health} />;
-      case 'total-emails': return <StatCard label="Total Emails" value={(data?.totalEmails ?? 0).toLocaleString()} to="/app/folder/allmail" />;
-      case 'unread-emails': return <StatCard label="Unread" value={(data?.unreadEmails ?? 0).toLocaleString()} to="/app/folder/unread" />;
-      case 'storage': return <StorageWidget bytes={data?.storageEstimateBytes} />;
-      case 'top-senders': return <TopSendersWidget senders={data?.topSenders} />;
-      case 'volume': return <VolumeWidget volume={data?.volumeOverTime} />;
-      case 'category-heatmap': return <CategoryHeatmapWidget />;
-      case 'attachments': return <AttachmentsWidget attachments={data?.attachmentBreakdown} />;
+      case 'inbox-health': return <HealthWidget health={data.health} />;
+      case 'total-emails': return <StatCard label="Total Emails" value={(data.totalEmails ?? 0).toLocaleString()} to="/app/folder/allmail" />;
+      case 'unread-emails': return <StatCard label="Unread" value={(data.unreadEmails ?? 0).toLocaleString()} to="/app/folder/unread" />;
+      case 'storage': return <StorageWidget bytes={data.storageEstimateBytes} />;
+      case 'top-senders': return <TopSendersWidget senders={data.topSenders} />;
+      case 'volume': return <VolumeWidget volume={data.volumeOverTime} />;
+      case 'attachments': return <AttachmentsWidget attachments={data.attachmentBreakdown} />;
       default: return null;
     }
   };