feat: implement dashboard page and add loading skeletons for all dashboard modules

src/app/(dashboard)/dashboard/loading.tsx

@@ -0,0 +1,27 @@
+export default function DashboardLoading() {
+    return (
+        <div className="flex flex-col gap-6 animate-pulse">
+            {/* Header skeleton */}
+            <div className="flex items-center justify-between">
+                <div className="h-7 w-48 rounded-lg bg-[var(--bg-elevated)]" />
+                <div className="h-5 w-32 rounded-lg bg-[var(--bg-elevated)]" />
+            </div>
+
+            {/* KPI cards row */}
+            <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
+                {Array.from({ length: 4 }).map((_, i) => (
+                    <div key={i} className="h-28 rounded-2xl bg-[var(--bg-elevated)] border border-[var(--border)]" />
+                ))}
+            </div>
+
+            {/* Main content area */}
+            <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
+                <div className="h-64 rounded-2xl bg-[var(--bg-elevated)] border border-[var(--border)]" />
+                <div className="h-64 rounded-2xl bg-[var(--bg-elevated)] border border-[var(--border)]" />
+            </div>
+
+            {/* Bottom tables */}
+            <div className="h-80 rounded-2xl bg-[var(--bg-elevated)] border border-[var(--border)]" />
+        </div>
+    );
+}

src/app/(dashboard)/dashboard/page.tsx

@@ -1,4 +1,11 @@
 import { pgGetDashboardData, type DashboardTopItem, type DashboardSiteStats, type DashboardSiteTop10 } from "@/lib/pg-ff-client";
+import { unstable_cache } from "next/cache";
+
+const getCachedDashboardData = unstable_cache(
+    pgGetDashboardData,
+    ["dashboard-data"],
+    { revalidate: 600 } // 10 minutes
+);
 import { TrendingUp, TrendingDown, Minus, Store, Euro, Users, ShoppingCart, Award, BarChart3 } from "lucide-react";
 
 // ---------------------------------------------------------------------------
@@ -722,7 +729,7 @@ function SectionHeader({ label, sub }: { label: string; sub?: string }) {
 export default async function DashboardPage() {
     let data;
     try {
-        data = await pgGetDashboardData();
+        data = await getCachedDashboardData();
     } catch (e) {
         const msg = e instanceof Error ? e.message : String(e);
         console.error("[Dashboard] pgGetDashboardData failed:", e);