feat(members): add members listing page

This commit introduces a new `/members` page to display a directory of alumni association members.

- Member data is sourced from a CSV file (`content/members/members.csv`) and managed via Nuxt Content.
- The page presents member information in a table, including calculated graduation class (`届别`).
- A link to the new page has been added to the main navigation.
- Minor UI tweaks and data corrections in other sections are also included.

app/layouts/default.vue

@@ -105,6 +105,11 @@ const bannerActions = ref<ButtonProps[]>([
 const items = computed<NavigationMenuItem[]>(() => [
   { label: "首页", to: "/" },
   { label: "新闻", to: "/news", active: route.path.startsWith("/news") },
+  {
+    label: "会员",
+    to: "/members",
+    active: route.path.startsWith("/members"),
+  },
   {
     label: "活动",
     to: "/events",
@@ -122,7 +127,7 @@ const items = computed<NavigationMenuItem[]>(() => [
     ],
   },
   {
-    label: "关于校友会",
+    label: "关于",
     to: "/about",
     active: route.path.startsWith("/about"),
     children: [
@@ -143,12 +148,12 @@ const items = computed<NavigationMenuItem[]>(() => [
         description: "永平中学补习班（1956年）：一封迟来的贴文",
         to: "/about/middle-highschool-tuition-class",
         active: route.path.startsWith("/about/middle-highschool-tuition-class"),
-        icon: "mdi:mail"
-      }
+        icon: "mdi:mail",
+      },
     ],
   },
   {
-    label: "友情链接",
+    label: "链接",
     children: [
       {
         label: "永平中学官网",