feat(admin): add initial admin dashboard structure

This commit introduces the foundational structure for the new admin dashboard.

- Utilizes @nuxt/ui to build the dashboard layout, including a collapsible sidebar and navigation.
- Adds initial pages for the dashboard, news, events, and hall of fame management.
- Implements a composable `useDashboardSidebarLinks` for managing sidebar navigation.
- Refactors the default layout by integrating the header and footer directly.
- Swaps the primary and secondary theme colors across the application.

app/composables/useDashboardSidebarLinks.ts

@@ -0,0 +1,56 @@
+import type { NavigationMenuItem } from "@nuxt/ui";
+
+export const useDashboardSidebarLinks = () => {
+  const sidebarLinks = [
+    [
+      {
+        label: "回到主站",
+        icon: "mdi:home",
+        type: "link",
+        to: "/",
+        target: "_blank"
+      },
+      {
+        label: "仪表盘",
+        icon: "mdi:view-dashboard",
+        to: "/admin/dashboard",
+      },
+      {
+        label: "内容管理",
+        icon: "mdi:bookshelf",
+        defaultOpen: true,
+        type: "trigger",
+        children: [
+          {
+            label: "新闻",
+            icon: "mdi:newspaper",
+            to: "/admin/contents/news",
+          },
+          {
+            label: "活动",
+            icon: "mdi:event",
+            to: "/admin/contents/events",
+          },
+          {
+            label: "名人堂",
+            icon: "mdi:trophy-award",
+            to: "/admin/contents/hall-of-fames",
+          },
+        ],
+      },
+      // {
+      //   label: "Settings",
+      //   to: "/settings",
+      //   icon: "mdi:cog",
+      //   defaultOpen: true,
+      //   type: "trigger",
+      //   children: [
+      //     { label: "General", icon: "mdi:tune", to: "/settings", exact: true },
+      //     { label: "Advanced", icon: "mdi:flask", to: "/settings/advanced" },
+      //   ],
+      // },
+    ],
+  ] satisfies NavigationMenuItem[][];
+
+  return { sidebarLinks };
+};