feat: implement shared LoadingModal component and integrate into dashboard route loading states

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

@@ -1,18 +1,5 @@
-export default function SnapshotsLoading() {
-    return (
-        <div className="flex flex-col gap-6 animate-pulse">
-            {/* Header */}
-            <div className="flex items-center justify-between">
-                <div className="h-7 w-36 rounded-lg bg-[var(--bg-elevated)]" />
-                <div className="h-9 w-36 rounded-lg bg-[var(--bg-elevated)]" />
-            </div>
+import LoadingModal from "@/components/shared/loading-modal";
 
-            {/* Cards grid */}
-            <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-                {Array.from({ length: 6 }).map((_, i) => (
-                    <div key={i} className="h-36 rounded-2xl bg-[var(--bg-elevated)] border border-[var(--border)]" />
-                ))}
-            </div>
-        </div>
-    );
+export default function SnapshotsLoading() {
+    return <LoadingModal message="Chargement des données" subMessage="Récupération des snapshots..." />;
 }