chore: 去掉未上线前的旧兼容垫片，板块流收口到首页

鉴权只认 cookie、SEO 只走 Next、sort 与推荐对齐；删除 Bearer、Go sitemap、post_type 回填等冗余路径。

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

frontend/app/admin/moderation/ModerationAdmin.tsx

@@ -270,7 +270,7 @@ export default function ModerationAdmin({
                   <div key={p.id} className="panel p-4 sm:p-5">
                     <div className="flex items-center gap-2 flex-wrap mb-2.5">
                       <Link
-                        href={`/board/${p.board.id}`}
+                        href={`/?board=${p.board.id}`}
                         className="chip"
                         style={{ fontSize: 11.5 }}
                       >
@@ -354,7 +354,7 @@ export default function ModerationAdmin({
                         {c.user.nickname}
                       </span>
                       <Link
-                        href={`/board/${c.board.id}`}
+                        href={`/?board=${c.board.id}`}
                         className="chip"
                         style={{ fontSize: 11 }}
                       >