feat: introduce new app routes with modular structure and enhanced features

Added modular app routes including `login`, `dashboard`, `categories`, `trends`, and `upload`. Introduced reusable components such as `ContentList`, `ContentSkeleton`, and `AppSidebar` for improved UI consistency. Enhanced authentication with `AuthProvider` and implemented lazy loading, dynamic layouts, and infinite scrolling for better performance.

frontend/src/app/(dashboard)/@modal/(.)meme/[slug]/page.tsx

@@ -0,0 +1,45 @@
+"use client";
+
+import * as React from "react";
+import { useRouter } from "next/navigation";
+import { Dialog, DialogContent, DialogTitle, DialogDescription } from "@/components/ui/dialog";
+import { ContentService } from "@/services/content.service";
+import { ContentCard } from "@/components/content-card";
+import type { Content } from "@/types/content";
+import { Spinner } from "@/components/ui/spinner";
+
+export default function MemeModal({ params }: { params: Promise<{ slug: string }> }) {
+  const { slug } = React.use(params);
+  const router = useRouter();
+  const [content, setContent] = React.useState<Content | null>(null);
+  const [loading, setLoading] = React.useState(true);
+
+  React.useEffect(() => {
+    ContentService.getOne(slug)
+      .then(setContent)
+      .catch(console.error)
+      .finally(() => setLoading(false));
+  }, [slug]);
+
+  return (
+    <Dialog open onOpenChange={(open) => !open && router.back()}>
+      <DialogContent className="max-w-3xl p-0 overflow-hidden bg-transparent border-none">
+        <DialogTitle className="sr-only">{content?.title || "Détail du mème"}</DialogTitle>
+        <DialogDescription className="sr-only">Affiche le mème en grand avec ses détails</DialogDescription>
+        {loading ? (
+          <div className="h-[500px] flex items-center justify-center bg-zinc-950/50 rounded-lg">
+            <Spinner className="h-10 w-10 text-white" />
+          </div>
+        ) : content ? (
+          <div className="bg-white dark:bg-zinc-900 rounded-lg overflow-hidden">
+            <ContentCard content={content} />
+          </div>
+        ) : (
+          <div className="p-8 bg-white dark:bg-zinc-900 rounded-lg text-center">
+            <p>Impossible de charger ce mème.</p>
+          </div>
+        )}
+      </DialogContent>
+    </Dialog>
+  );
+}