feat: 全站评论开关，并统一后台表单控件

关闭评论后前台隐藏评论能力；外观/设置/公告改用 AdminField 与 Stepper。

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

frontend/components/CommentSection.tsx

@@ -6,7 +6,6 @@ import Link from "next/link";
 import {
   Trash2,
   MessagesSquare,
-  MessageSquareOff,
   ChevronRight,
   ChevronDown,
   BadgeCheck,
@@ -31,7 +30,8 @@ import {
 } from "@/lib/api";
 import { canModerateBoard } from "@/lib/roles";
 import { toast } from "@/lib/toast";
-import { realtime, RT_SETTINGS_CHANGED, type RtSettingsData } from "@/lib/realtime";
+import { useAllowComments } from "@/components/CommentsPolicyProvider";
+import CommentsUnsupported from "@/components/CommentsUnsupported";
 import Avatar from "./Avatar";
 import Pagination from "./Pagination";
 import MarkdownBodyClient from "@/components/MarkdownBodyClient";
@@ -57,8 +57,6 @@ interface CommentSectionProps {
   acceptedCommentId?: number;
   /** 抽奖已开奖：中奖楼层评论 ID（每名中奖者仅其最早主评一条） */
   winnerCommentIds?: number[];
-  /** 全站是否开放评论；缺省 true。关闭时隐藏发评/回复入口 */
-  allowComments?: boolean;
 }
 
 // 递归统计子树回复数（彻底删除级联提示用）
@@ -116,10 +114,10 @@ export default function CommentSection({
   acceptMode = null,
   acceptedCommentId = 0,
   winnerCommentIds = [],
-  allowComments: allowCommentsProp = true,
 }: CommentSectionProps) {
   const winnerCommentIdSet = new Set(winnerCommentIds.filter((id) => id > 0));
   const router = useRouter();
+  const commentsOpen = useAllowComments();
   const [content, setContent] = useState("");
   // 内联回复目标：在该评论下方就地发子评论（同一时间只有一个回复框）
   const [replyTarget, setReplyTarget] = useState<{ id: number; nickname: string } | null>(null);
@@ -141,25 +139,14 @@ export default function CommentSection({
   const [historyCommentId, setHistoryCommentId] = useState<number | null>(null);
   // 折叠状态：哪些楼层展开了子回复（默认全部折叠，SSR 初始为收起）
   const [expandedFloors, setExpandedFloors] = useState<Set<number>>(new Set());
-  const [commentsOpen, setCommentsOpen] = useState(allowCommentsProp !== false);
   const textareaRef = useRef<HTMLTextAreaElement>(null);
 
   useEffect(() => {
-    setCommentsOpen(allowCommentsProp !== false);
-  }, [allowCommentsProp]);
-
-  // 管理后台开关变更后即时隐藏发评入口（后端仍硬拒绝）
-  useEffect(() => {
-    return realtime.on<RtSettingsData>(RT_SETTINGS_CHANGED, (data) => {
-      if (typeof data?.allow_comments === "boolean") {
-        setCommentsOpen(data.allow_comments);
-        if (!data.allow_comments) {
-          setReplyTarget(null);
-          setReplyContent("");
-        }
-      }
-    });
-  }, []);
+    if (!commentsOpen) {
+      setReplyTarget(null);
+      setReplyContent("");
+    }
+  }, [commentsOpen]);
 
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault();
@@ -1017,6 +1004,10 @@ export default function CommentSection({
     );
   };
 
+  if (!commentsOpen) {
+    return <CommentsUnsupported />;
+  }
+
   return (
     <section className="panel p-6 sm:p-8 mt-6" aria-label="评论区">
       <div className="flex items-center gap-2.5 mb-6">
@@ -1032,34 +1023,7 @@ export default function CommentSection({
         <span className="meta ml-auto text-[11.5px]">共 {totalPages} 页楼层</span>
       </div>
 
-      {!commentsOpen ? (
-        <div
-          className="mb-8 rounded-2xl border px-5 py-6 text-center sm:px-6"
-          style={{
-            borderColor: "color-mix(in srgb, var(--ink-3) 35%, var(--line))",
-            background:
-              "repeating-linear-gradient(-45deg, transparent, transparent 6px, color-mix(in srgb, var(--ink-3) 8%, transparent) 6px, color-mix(in srgb, var(--ink-3) 8%, transparent) 7px), var(--panel-2)",
-          }}
-          role="status"
-        >
-          <span
-            className="mx-auto mb-3 flex h-11 w-11 items-center justify-center rounded-xl"
-            style={{
-              background: "color-mix(in srgb, var(--ink-3) 14%, transparent)",
-              color: "var(--ink-3)",
-            }}
-            aria-hidden
-          >
-            <MessageSquareOff size={22} />
-          </span>
-          <p className="text-[15px] font-semibold" style={{ color: "var(--ink)" }}>
-            评论功能暂时关闭
-          </p>
-          <p className="meta mt-1.5 text-[12.5px] leading-relaxed">
-            站点当前暂停发表新评论与回复，历史评论仍可浏览。
-          </p>
-        </div>
-      ) : user ? (
+      {user ? (
         <form onSubmit={handleSubmit} className="mb-8">
           <textarea
             ref={textareaRef}
@@ -1106,9 +1070,7 @@ export default function CommentSection({
             <p className="text-sm" style={{ color: "var(--ink-2)" }}>
               暂无评论
             </p>
-            <p className="meta text-[12.5px] mt-1">
-              {commentsOpen ? "来说两句，抢占沙发" : "评论开放后即可参与讨论"}
-            </p>
+            <p className="meta text-[12.5px] mt-1">来说两句，抢占沙发</p>
           </div>
         )}
       </div>