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)/trends/page.tsx

@@ -0,0 +1,17 @@
+import * as React from "react";
+import type { Metadata } from "next";
+import { ContentList } from "@/components/content-list";
+import { ContentService } from "@/services/content.service";
+
+export const metadata: Metadata = {
+  title: "Tendances | MemeGoat",
+  description: "Découvrez les mèmes les plus populaires du moment sur MemeGoat.",
+};
+
+export default function TrendsPage() {
+  const fetchFn = React.useCallback((params: { limit: number; offset: number }) => 
+    ContentService.getTrends(params.limit, params.offset), 
+  []);
+
+  return <ContentList fetchFn={fetchFn} title="Top Tendances" />;
+}