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.

docs/PPT Designs v1.md

@@ -63,7 +63,7 @@
 
 - 版式：16:9，黑/深灰背景或浅色质感底，突出橙色点缀
 - 字体：中文优先思源黑体/Noto Sans SC；标题粗体、正文中等
-- 统一元素：使用 public/Logo.svg 与 public/hero-image.jpg 作封面/过渡图
+- 统一元素：使用 public/Logo.svg 与 public/hero-image-2.jpg 作封面/过渡图
 - 图片素材：新闻/活动封面取自 public/news/*、public/events/*、public/hall-of-fame/*
 - 最少字多图：每页 3–5 条要点，每条不超过一行半
 
@@ -82,7 +82,7 @@
 
 素材清单（制作 PPT 前先备齐）
 
-- Logo 与主视觉：public/Logo.svg、public/hero-image.jpg
+- Logo 与主视觉：public/Logo.svg、public/hero-image-2.jpg
 - 二维码：yphsalumni.org（建议白底黑码，配校色边框）
 - 页面截图：主页、新闻、活动、名人堂、入会、后台
 - 文案确认：宗旨口号、愿景 1 句话、路线图 3–5 条