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.

nuxt.config.ts

@@ -50,7 +50,7 @@ export default defineNuxtConfig({
         { property: "og:url", content: "https://yphsalumni.org" }, // ✅ 换成你网站的真实域名
         {
           property: "og:image",
-          content: "https://yphsalumni.org/hero-image.jpg",
+          content: "https://yphsalumni.org/hero-image-2.jpg",
         }, // ✅ 上传一张封面图
 
         // Twitter Card
@@ -62,7 +62,7 @@ export default defineNuxtConfig({
         },
         {
           name: "twitter:image",
-          content: "https://yphsalumni.org/hero-image.jpg",
+          content: "https://yphsalumni.org/hero-image-2.jpg",
         },
       ],
     },