feat: 移除「关于本站」按钮与功能

- PublicLayout: 删除桌面导航/下拉菜单/页脚三处入口及空页脚,移除 about 导航类型与判断
- App: 移除 /about 路由及 AboutPage 引入
- 删除 pages/About 页面
- DocumentMeta: 移除 /about 的 meta 处理与 about 描述文案(中/英)
- i18n: 移除 aboutTitle / aboutIntro / footerAbout(中/英)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/layouts/PublicLayout.tsx

@@ -17,8 +17,7 @@ type PublicNavWhich =
   | "browseLatest"
   | "browseRecommended"
   | "browsePopular"
-  | "favorites"
-  | "about";
+  | "favorites";
 
 function navIsActive(
   pathname: string,
@@ -47,8 +46,6 @@ function navIsActive(
       return (
         pathname === "/favorites" || (pathname === "/" && hash === "#favorites")
       );
-    case "about":
-      return pathname === "/about";
     default:
       return false;
   }
@@ -477,13 +474,6 @@ export function PublicLayout() {
               >
                 {t("favorites")}
               </Link>
-              <Link
-                to="/about"
-                className={navClassName(na("about"))}
-                aria-current={na("about") ? "page" : undefined}
-              >
-                {t("footerAbout")}
-              </Link>
             </nav>
 
             <div className="flex min-w-0 flex-1 items-center justify-end gap-2 min-[1200px]:flex-none">
@@ -593,14 +583,6 @@ export function PublicLayout() {
             >
               {t("favorites")}
             </Link>
-            <Link
-              to="/about"
-              className={navClassName(na("about"))}
-              aria-current={na("about") ? "page" : undefined}
-              onClick={() => setOpen(false)}
-            >
-              {t("footerAbout")}
-            </Link>
           </div>
         ) : null}
       </header>
@@ -637,19 +619,6 @@ export function PublicLayout() {
         </AnimatePresence>
       </main>
 
-      <footer className="mt-auto bg-transparent md:border-t md:border-ark-line md:bg-ark-nav/90">
-        <div className="mx-auto flex h-[52px] max-w-[358px] items-center justify-center px-4 py-4 text-[13px] leading-5 md:h-auto md:max-w-[1280px] md:justify-start md:px-9 md:py-6 md:text-sm xl:px-0">
-          <Link
-            to="/about"
-            className={`rounded-sm outline-none hover:text-ark-gold2 focus-visible:ring-2 focus-visible:ring-ark-gold/80 focus-visible:ring-offset-2 focus-visible:ring-offset-ark-bg ${
-              na("about") ? "text-ark-gold" : "text-[#A8A9AE]"
-            }`}
-          >
-            {t("footerAbout")}
-          </Link>
-        </div>
-      </footer>
-
       <nav className="sticky inset-x-0 bottom-0 z-40 bg-[#0C0D0F]/90 backdrop-blur md:hidden">
         <div className="grid h-[78px] grid-cols-4 gap-3 px-5 py-4 text-center text-[11px] leading-[17.6px]">
           <BottomNavIcon