公开页补齐自引用 Canonical 与按类型的结构化数据，图片补上说明文字。

后台设置和内容编辑改成可导航布局；部署用访客 origin 生成 Canonical，避免落到容器地址。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/components/home/FeedTabs.tsx

@@ -10,11 +10,12 @@ export type FeedSort = "latest" | "new" | "recommended";
 
 const TAB_KEYS: FeedSort[] = ["latest", "new", "recommended"];
 
-// 在指定板块内切换排序时保留 ?board=
-function tabHref(key: FeedSort, boardId: number) {
+// 在指定板块内切换排序时保留 ?board=；默认排序不写入 URL
+function tabHref(key: FeedSort, boardId: number, allowComments: boolean) {
   const params = new URLSearchParams();
   if (boardId > 0) params.set("board", String(boardId));
-  if (key !== "latest") params.set("sort", key);
+  const def = allowComments ? "latest" : "new";
+  if (key !== def) params.set("sort", key);
   const qs = params.toString();
   return qs ? `/?${qs}` : "/";
 }
@@ -31,7 +32,7 @@ export default function FeedTabs({ current, boardId = 0 }: { current: FeedSort;
     e.preventDefault();
     const next = (i + (e.key === "ArrowRight" ? 1 : keys.length - 1)) % keys.length;
     tabRefs.current[next]?.focus();
-    router.push(tabHref(keys[next], boardId));
+    router.push(tabHref(keys[next], boardId, allowComments));
   };
 
   return (
@@ -44,7 +45,7 @@ export default function FeedTabs({ current, boardId = 0 }: { current: FeedSort;
             ref={(el) => {
               tabRefs.current[i] = el;
             }}
-            href={tabHref(key, boardId)}
+            href={tabHref(key, boardId, allowComments)}
             role="tab"
             className="j13-tab inline-flex items-center gap-1"
             aria-selected={current === key}