feat: 后台增加开放消息开关

关闭后前台隐藏私聊/群聊入口并由后端拦截；同步去掉公告页重复计数胶囊。

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

backend/handler/auth.go

@@ -279,7 +279,12 @@ func (h *Handlers) Me(c *gin.Context) {
 	if n, err := h.Notification.UnreadCount(claims.ID); err == nil {
 		unread = n
 	}
-	chatUnread := h.Chat.TotalUnread(claims.ID)
+	chatUnread := int64(0)
+	if h.Setting != nil && h.Chat != nil {
+		if allow, err := h.Setting.AllowMessages(); err == nil && allow {
+			chatUnread = h.Chat.TotalUnread(claims.ID)
+		}
+	}
 	// 板块管理员带出授权板块，供前端菜单/按钮按板块范围渲染
 	var boardIDs []uint
 	if user.Role == model.RoleBoardAdmin {

backend/handler/chat.go

@@ -47,6 +47,24 @@ func (h *Handlers) chatOversee(userID uint) bool {
 	return service.CanOverseeChat(actor.Role)
 }
 
+// RequireMessagesOpen 前台群聊/私聊闸门；关闭后一律 403。管理端 /api/admin/chat 不受影响。
+func (h *Handlers) RequireMessagesOpen(c *gin.Context) {
+	if h.Setting == nil {
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"error": "消息暂时不可用"})
+		return
+	}
+	allow, err := h.Setting.AllowMessages()
+	if err != nil {
+		c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"error": "消息暂时不可用"})
+		return
+	}
+	if !allow {
+		c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"error": "本站不支持消息"})
+		return
+	}
+	c.Next()
+}
+
 // CreateChatRoom 建群（可公开/私密，私密可带初始成员）
 func (h *Handlers) CreateChatRoom(c *gin.Context) {
 	claims := middleware.CurrentUser(c)

backend/handler/setting.go

@@ -27,6 +27,7 @@ type updateSettingsRequest struct {
 	SiteDescription      *string `json:"site_description"`
 	AllowRegister        *bool   `json:"allow_register"`
 	AllowComments        *bool   `json:"allow_comments"`
+	AllowMessages        *bool   `json:"allow_messages"`
 	PostCooldownHours    *int    `json:"post_cooldown_hours"`
 	CodeBlockAutoFold    *bool   `json:"code_block_auto_fold"`
 	CodeBlockFoldLines   *int    `json:"code_block_fold_lines"`
@@ -45,6 +46,7 @@ func settingsPayload(saved service.PublicSiteSettings) gin.H {
 		"site_description":       saved.SiteDescription,
 		"allow_register":         saved.AllowRegister,
 		"allow_comments":         saved.AllowComments,
+		"allow_messages":         saved.AllowMessages,
 		"post_cooldown_hours":    saved.PostCooldownHours,
 		"code_block_auto_fold":   saved.CodeBlockAutoFold,
 		"code_block_fold_lines":  saved.CodeBlockFoldLines,
@@ -65,6 +67,7 @@ func (h *Handlers) UpdateSettings(c *gin.Context) {
 	}
 	if req.Accent == nil && req.TrustReviewedPublish == nil && req.SiteName == nil &&
 		req.SiteDescription == nil && req.AllowRegister == nil && req.AllowComments == nil &&
+		req.AllowMessages == nil &&
 		req.PostCooldownHours == nil && req.CodeBlockAutoFold == nil && req.CodeBlockFoldLines == nil &&
 		req.UIAnimations == nil && req.AnimCodeFold == nil && req.AnimSmoothScroll == nil &&
 		req.AnimChrome == nil && req.PostLinkNewTab == nil {
@@ -120,6 +123,12 @@ func (h *Handlers) UpdateSettings(c *gin.Context) {
 			return
 		}
 	}
+	if req.AllowMessages != nil {
+		if err := h.Setting.SetAllowMessages(*req.AllowMessages); err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "保存站点设置失败"})
+			return
+		}
+	}
 	if req.PostCooldownHours != nil {
 		if err := h.Setting.SetPostCooldownHours(*req.PostCooldownHours); err != nil {
 			if errors.Is(err, service.ErrInvalidSiteSetting) {

backend/router/router.go

@@ -179,25 +179,28 @@ func Setup(cfg *config.Config) (*gin.Engine, error) {
 		api.GET("/my/media", h.MyMedia)
 		api.DELETE("/my/attachments/:id", h.DeleteAttachment)
 
-		// 群聊（二期）：建群/成员/消息/未读
+		// 群聊（二期）：建群/成员/消息/未读；全站关闭消息时前台一律 403
-		api.GET("/chat/rooms", h.ListChatRooms)
+		chatAPI := api.Group("/chat", h.RequireMessagesOpen)
-		api.POST("/chat/rooms", h.CreateChatRoom)
+		{
-		api.POST("/chat/direct", h.OpenDirectChat)
+			chatAPI.GET("/rooms", h.ListChatRooms)
-		api.GET("/chat/users", h.SearchChatUsers)
+			chatAPI.POST("/rooms", h.CreateChatRoom)
-		api.GET("/chat/rooms/:id", h.GetChatRoom)
+			chatAPI.POST("/direct", h.OpenDirectChat)
-		api.PUT("/chat/rooms/:id", h.UpdateChatRoom)
+			chatAPI.GET("/users", h.SearchChatUsers)
-		api.PUT("/chat/rooms/:id/pin", h.PinChatRoom)
+			chatAPI.GET("/rooms/:id", h.GetChatRoom)
-		api.DELETE("/chat/rooms/:id", h.DissolveChatRoom)
+			chatAPI.PUT("/rooms/:id", h.UpdateChatRoom)
-		api.POST("/chat/rooms/:id/join", h.JoinChatRoom)
+			chatAPI.PUT("/rooms/:id/pin", h.PinChatRoom)
-		api.POST("/chat/rooms/:id/leave", h.LeaveChatRoom)
+			chatAPI.DELETE("/rooms/:id", h.DissolveChatRoom)
-		api.GET("/chat/rooms/:id/members", h.ListChatMembers)
+			chatAPI.POST("/rooms/:id/join", h.JoinChatRoom)
-		api.POST("/chat/rooms/:id/members", h.InviteChatMembers)
+			chatAPI.POST("/rooms/:id/leave", h.LeaveChatRoom)
-		api.DELETE("/chat/rooms/:id/members/:uid", h.KickChatMember)
+			chatAPI.GET("/rooms/:id/members", h.ListChatMembers)
-		api.GET("/chat/rooms/:id/messages", h.ListChatMessages)
+			chatAPI.POST("/rooms/:id/members", h.InviteChatMembers)
-		api.POST("/chat/rooms/:id/messages", middleware.RateLimitMiddleware(limiter, service.RateChat), h.SendChatMessage)
+			chatAPI.DELETE("/rooms/:id/members/:uid", h.KickChatMember)
-		api.DELETE("/chat/rooms/:id/messages/:mid", h.RecallChatMessage)
+			chatAPI.GET("/rooms/:id/messages", h.ListChatMessages)
-		api.PUT("/chat/rooms/:id/read", h.MarkChatRead)
+			chatAPI.POST("/rooms/:id/messages", middleware.RateLimitMiddleware(limiter, service.RateChat), h.SendChatMessage)
-		api.GET("/chat/unread-summary", h.ChatUnreadSummary)
+			chatAPI.DELETE("/rooms/:id/messages/:mid", h.RecallChatMessage)
+			chatAPI.PUT("/rooms/:id/read", h.MarkChatRead)
+			chatAPI.GET("/unread-summary", h.ChatUnreadSummary)
+		}
 	}
 
 	// 管理后台 API：RequireStaff 基础鉴权（板块管理员及以上，Actor 实时从 DB 现取），

backend/service/setting.go

@@ -22,6 +22,8 @@ const (
 	SettingKeyAllowRegister        = "allow_register"
 	// SettingKeyAllowComments 全站开放评论；缺行视为开启（默认开）
 	SettingKeyAllowComments = "allow_comments"
+	// SettingKeyAllowMessages 全站开放私聊/群聊；缺行视为开启（默认开）
+	SettingKeyAllowMessages     = "allow_messages"
 	SettingKeyPostCooldownHours = "post_cooldown_hours"
 	// SettingKeyCodeBlockAutoFold 代码块自动折叠；缺行视为开启
 	SettingKeyCodeBlockAutoFold = "code_block_auto_fold"
@@ -67,6 +69,7 @@ type PublicSiteSettings struct {
 	SiteDescription      string `json:"site_description"`
 	AllowRegister        bool   `json:"allow_register"`
 	AllowComments        bool   `json:"allow_comments"`
+	AllowMessages        bool   `json:"allow_messages"`
 	PostCooldownHours    int    `json:"post_cooldown_hours"`
 	CodeBlockAutoFold    bool   `json:"code_block_auto_fold"`
 	CodeBlockFoldLines   int    `json:"code_block_fold_lines"`
@@ -135,6 +138,7 @@ func (s *SettingService) Public() (PublicSiteSettings, error) {
 		TrustReviewedPublish: true,
 		AllowRegister:        true,
 		AllowComments:        true,
+		AllowMessages:        true,
 		PostCooldownHours:    DefaultCooldownHours,
 		CodeBlockAutoFold:    true,
 		CodeBlockFoldLines:   DefaultCodeFoldLines,
@@ -187,6 +191,12 @@ func (s *SettingService) Public() (PublicSiteSettings, error) {
 	}
 	out.AllowComments = comments
 
+	messages, err := s.AllowMessages()
+	if err != nil {
+		return out, err
+	}
+	out.AllowMessages = messages
+
 	hours, err := s.PostCooldownHours()
 	if err != nil {
 		return out, err
@@ -320,6 +330,20 @@ func (s *SettingService) SetAllowComments(on bool) error {
 	return s.setBoolDefaultTrue(SettingKeyAllowComments, on)
 }
 
+// AllowMessages 是否允许全站私聊/群聊。缺行视为开启。
+func (s *SettingService) AllowMessages() (bool, error) {
+	v, found, err := s.getValue(SettingKeyAllowMessages)
+	if err != nil {
+		return true, err
+	}
+	return parseBoolDefaultTrue(v, found), nil
+}
+
+// SetAllowMessages 持久化消息开关；开启时删键保持「缺行=默认开」。
+func (s *SettingService) SetAllowMessages(on bool) error {
+	return s.setBoolDefaultTrue(SettingKeyAllowMessages, on)
+}
+
 // PostCooldownHours 新用户发帖冷静期（小时）。缺行=24；0 表示关闭。
 func (s *SettingService) PostCooldownHours() (int, error) {
 	v, found, err := s.getValue(SettingKeyPostCooldownHours)

frontend/app/admin/announcements/AnnouncementAdmin.tsx

@@ -334,28 +334,7 @@ export default function AnnouncementAdmin({
         }
       />
 
-      {/* 计数条 */}
+      <div className="mb-4">
-      <div className="flex items-center gap-3 mb-4 flex-wrap">
-        <div
-          className="inline-flex items-center gap-4 rounded-lg px-3.5 py-2 text-[13px]"
-          style={{ background: "var(--panel-2)", color: "var(--ink-2)" }}
-        >
-          <span>
-            草稿{" "}
-            <strong className="tabular-nums" style={{ color: "var(--ink)" }}>
-              {draftCount}
-            </strong>
-          </span>
-          <span aria-hidden style={{ color: "var(--line)" }}>
-            |
-          </span>
-          <span>
-            已发布{" "}
-            <strong className="tabular-nums" style={{ color: "var(--ink)" }}>
-              {publishedCount}
-            </strong>
-          </span>
-        </div>
         <AdminSegmented<StatusFilter>
           ariaLabel="公告状态筛选"
           size="sm"

frontend/app/admin/settings/SettingsAdmin.tsx

@@ -6,6 +6,7 @@ import {
   MessageSquare,
   Save,
   UserPlus,
+  MessagesSquare,
   ExternalLink,
   Shield,
   Mail,
@@ -107,12 +108,14 @@ export default function SettingsAdmin({ initial }: { initial: PublicSettings })
   const [siteDescription, setSiteDescription] = useState(initial.site_description);
   const [allowRegister, setAllowRegister] = useState(initial.allow_register);
   const [allowComments, setAllowComments] = useState(initial.allow_comments !== false);
+  const [allowMessages, setAllowMessages] = useState(initial.allow_messages !== false);
   const [postLinkNewTab, setPostLinkNewTab] = useState(initial.post_link_new_tab !== false);
   const [savedName, setSavedName] = useState(initial.site_name);
   const [savedDesc, setSavedDesc] = useState(initial.site_description);
   const [saving, setSaving] = useState(false);
   const [togglingReg, setTogglingReg] = useState(false);
   const [togglingComments, setTogglingComments] = useState(false);
+  const [togglingMessages, setTogglingMessages] = useState(false);
   const [togglingLink, setTogglingLink] = useState(false);
   const [active, setActive] = useState<SectionId>("basic");
 
@@ -199,6 +202,21 @@ export default function SettingsAdmin({ initial }: { initial: PublicSettings })
     }
   };
 
+  const toggleMessages = async () => {
+    if (togglingMessages) return;
+    const next = !allowMessages;
+    setTogglingMessages(true);
+    try {
+      const res = await apiUpdateSiteSettings({ allow_messages: next });
+      setAllowMessages(res.allow_messages);
+      toast(res.allow_messages ? "已开放消息" : "已关闭消息", "ok");
+    } catch (e) {
+      toast(e instanceof Error ? e.message : "保存失败");
+    } finally {
+      setTogglingMessages(false);
+    }
+  };
+
   const togglePostLinkNewTab = async () => {
     if (togglingLink) return;
     const next = !postLinkNewTab;
@@ -293,7 +311,7 @@ export default function SettingsAdmin({ initial }: { initial: PublicSettings })
           </div>
 
           <div id="settings-content" className="scroll-mt-4">
-            <AdminSection title="内容与互动" description="控制注册、评论与链接打开方式">
+            <AdminSection title="内容与互动" description="控制注册、评论、消息与链接打开方式">
               <SwitchRow
                 bordered
                 title={
@@ -328,6 +346,23 @@ export default function SettingsAdmin({ initial }: { initial: PublicSettings })
                   />
                 }
               />
+              <SwitchRow
+                bordered
+                title={
+                  <>
+                    <MessagesSquare size={15} /> 开放消息
+                  </>
+                }
+                description="关闭后前台不展示私聊与群聊入口；已有会话由后台消息管理继续监管。"
+                control={
+                  <AdminSwitch
+                    checked={allowMessages}
+                    disabled={togglingMessages}
+                    onChange={() => void toggleMessages()}
+                    label="开放消息"
+                  />
+                }
+              />
               <SwitchRow
                 title={
                   <>

frontend/app/chat/[id]/page.tsx

@@ -2,10 +2,11 @@ import type { Metadata } from "next";
 import { notFound, redirect } from "next/navigation";
 import { cookies } from "next/headers";
 import { authCookieHeader } from "@/lib/cookies";
-import { getMeCached } from "@/lib/serverData";
+import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
 import { fetchChatRoom, fetchChatMessages, fetchChatRooms } from "@/lib/api";
 import ChatShell from "../ChatShell";
 import ChatRoomClient from "./ChatRoomClient";
+import MessagesUnsupported from "@/components/MessagesUnsupported";
 
 interface PageProps {
   params: Promise<{ id: string }>;
@@ -13,6 +14,9 @@ interface PageProps {
 
 export async function generateMetadata({ params }: PageProps): Promise<Metadata> {
   const { id } = await params;
+  if ((await getPublicSettingsCached()).allow_messages === false) {
+    return { title: "本站不支持消息" };
+  }
   try {
     const { room } = await fetchChatRoom(id, authCookieHeader(await cookies()));
     const title =
@@ -27,6 +31,9 @@ export async function generateMetadata({ params }: PageProps): Promise<Metadata>
 
 export default async function ChatRoomPage({ params }: PageProps) {
   const { id } = await params;
+  if ((await getPublicSettingsCached()).allow_messages === false) {
+    return <MessagesUnsupported />;
+  }
   const cookie = authCookieHeader(await cookies());
   const me = await getMeCached(cookie || undefined);
   if (!me.user) {

frontend/app/chat/page.tsx

@@ -2,9 +2,10 @@ import { redirect } from "next/navigation";
 import { cookies } from "next/headers";
 import type { Metadata } from "next";
 import { authCookieHeader } from "@/lib/cookies";
-import { getMeCached } from "@/lib/serverData";
+import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
 import { fetchChatRooms } from "@/lib/api";
 import ChatShell from "./ChatShell";
+import MessagesUnsupported from "@/components/MessagesUnsupported";
 
 export const metadata: Metadata = {
   title: "消息",
@@ -12,6 +13,9 @@ export const metadata: Metadata = {
 };
 
 export default async function ChatListPage() {
+  if ((await getPublicSettingsCached()).allow_messages === false) {
+    return <MessagesUnsupported />;
+  }
   const cookie = authCookieHeader(await cookies());
   const me = await getMeCached(cookie || undefined);
   if (!me.user) {

frontend/app/layout.tsx

@@ -13,6 +13,7 @@ import PostLinkProvider from "@/components/PostLinkProvider";
 import CodeFoldProvider from "@/components/markdown/CodeFoldProvider";
 import MotionProvider from "@/components/MotionProvider";
 import CommentsPolicyProvider from "@/components/CommentsPolicyProvider";
+import MessagesPolicyProvider from "@/components/MessagesPolicyProvider";
 import type { User } from "@/lib/api";
 import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
 import { TOKEN_COOKIE, authCookieHeader } from "@/lib/cookies";
@@ -121,6 +122,7 @@ export default async function RootLayout({
         </a>
         <MotionProvider initial={motionCfg}>
           <CommentsPolicyProvider allowComments={settings.allow_comments !== false}>
+            <MessagesPolicyProvider allowMessages={settings.allow_messages !== false}>
               <PostLinkProvider openInNewTab={settings.post_link_new_tab !== false}>
                 <CodeFoldProvider
                   initialEnabled={settings.code_block_auto_fold}
@@ -130,7 +132,7 @@ export default async function RootLayout({
                     initialIsAdmin={isAdmin}
                     user={user}
                     unread={unread}
-                  chatUnread={chatUnread}
+                    chatUnread={settings.allow_messages !== false ? chatUnread : 0}
                     theme={theme}
                     siteName={settings.site_name}
                     allowRegister={settings.allow_register}
@@ -139,6 +141,7 @@ export default async function RootLayout({
                   </SiteChrome>
                 </CodeFoldProvider>
               </PostLinkProvider>
+            </MessagesPolicyProvider>
           </CommentsPolicyProvider>
         </MotionProvider>
         <Toaster />

frontend/app/login/page.tsx

@@ -7,6 +7,7 @@ import { MessagesSquare } from "lucide-react";
 import { apiLogin, apiMe, apiGetSettings } from "@/lib/api";
 import { hasAuthCookieHint } from "@/lib/cookies";
 import { useAllowComments } from "@/components/CommentsPolicyProvider";
+import { useAllowMessages } from "@/components/MessagesPolicyProvider";
 
 // 仅允许同源相对路径跳转，拦截 //host、/\\host 与绝对 URL 形式的开放重定向
 function safeRedirect(to: string | null): string {
@@ -42,6 +43,7 @@ export default function LoginPage() {
   const router = useRouter();
   const searchParams = useSearchParams();
   const allowComments = useAllowComments();
+  const allowMessages = useAllowMessages();
   const redirect = safeRedirect(searchParams.get("redirect"));
   const [username, setUsername] = useState("");
   const [password, setPassword] = useState("");
@@ -93,7 +95,7 @@ export default function LoginPage() {
           欢迎回来
         </h1>
         <p className="text-sm mt-2" style={{ color: "var(--ink-2)" }}>
-          登录后发帖{allowComments ? "、评论" : ""}与点赞
+          登录后发帖{allowComments ? "、评论" : ""}{allowMessages ? "、发消息" : ""}与点赞
         </p>
       </div>
 

frontend/app/u/[id]/StartDMButton.tsx

@@ -5,12 +5,16 @@ import { useRouter } from "next/navigation";
 import { MessageSquare } from "lucide-react";
 import { apiOpenDirectChat } from "@/lib/api";
 import { toast } from "@/lib/toast";
+import { useAllowMessages } from "@/components/MessagesPolicyProvider";
 
 /** 用户主页：发起私聊 */
 export default function StartDMButton({ userId }: { userId: number }) {
   const router = useRouter();
+  const allowMessages = useAllowMessages();
   const [loading, setLoading] = useState(false);
 
+  if (!allowMessages) return null;
+
   const start = async () => {
     setLoading(true);
     try {

frontend/app/u/[id]/page.tsx

@@ -56,7 +56,9 @@ export default async function UserPage({ params, searchParams }: UserPageProps)
 
   const cookie = authCookieHeader(await cookies());
   const me = await getMeCached(cookie || undefined);
-  const allowComments = (await getPublicSettingsCached()).allow_comments !== false;
+  const settings = await getPublicSettingsCached();
+  const allowComments = settings.allow_comments !== false;
+  const allowMessages = settings.allow_messages !== false;
 
   let data: UserProfile;
   try {
@@ -172,7 +174,7 @@ export default async function UserPage({ params, searchParams }: UserPageProps)
                 banned: u.banned,
               }}
             />
-            <StartDMButton userId={data.user.id} />
+            {allowMessages ? <StartDMButton userId={data.user.id} /> : null}
           </div>
         ) : null}
 

frontend/components/Header.tsx

@@ -29,6 +29,7 @@ import { onDocumentVisible } from "@/lib/visibilityReconcile";
 import NotificationBell from "./NotificationBell";
 import ThemeToggle from "./ThemeToggle";
 import Avatar from "./Avatar";
+import { useAllowMessages } from "./MessagesPolicyProvider";
 
 export default function Header({
   initialUser,
@@ -47,6 +48,7 @@ export default function Header({
 }) {
   const router = useRouter();
   const pathname = usePathname();
+  const allowMessages = useAllowMessages();
   const [menuOpen, setMenuOpen] = useState(false);
   // 登录态以 SSR 直出为初始值，F5 无切换闪动；router.refresh() 后随 props 校正
   const [user, setUser] = useState<User | null>(initialUser);
@@ -105,7 +107,7 @@ export default function Header({
 
   // 实时未读：chat:unread 推送给所有成员（含未打开会话页）；在当前会话页则忽略
   useEffect(() => {
-    if (!user) return;
+    if (!user || !allowMessages) return;
     const off = realtime.on<RtChatUnreadData>(RT_CHAT_UNREAD, (data) => {
       if (!data || typeof data.room_id !== "number") return;
       if (pathname === `/chat/${data.room_id}`) return;
@@ -113,11 +115,11 @@ export default function Header({
       setChatUnread((c) => Math.max(0, c + delta));
     });
     return off;
-  }, [user, pathname]);
+  }, [user, pathname, allowMessages]);
 
   // 会话内已读 / 回前台：合并对账（短时间多次 markRead 只打一次 summary）
   useEffect(() => {
-    if (!user) return;
+    if (!user || !allowMessages) return;
     let debounceTimer: ReturnType<typeof setTimeout> | null = null;
     const pullSummary = () => {
       apiChatUnreadSummary()
@@ -135,7 +137,7 @@ export default function Header({
       window.removeEventListener("j13-chat-unread-sync", onSync);
       offVisible();
     };
-  }, [user]);
+  }, [user, allowMessages]);
 
   const handleSearch = (e: React.FormEvent) => {
     e.preventDefault();
@@ -271,7 +273,7 @@ export default function Header({
             className={`${iconBtn} hidden lg:inline-flex`}
             style={iconBtnStyle}
           />
-          {user && (
+          {user && allowMessages && (
             <Link
               href="/chat"
               prefetch={false}
@@ -359,7 +361,7 @@ export default function Header({
           <div className="flex flex-col">
             <MobileLink href="/" active={pathname === "/"}>首页</MobileLink>
             {user && <MobileLink href="/compose">发帖</MobileLink>}
-            {user && (
+            {user && allowMessages && (
               <MobileLink href="/chat" active={pathname?.startsWith("/chat") ?? false}>
                 <span className="inline-flex items-center gap-2">
                   <MessageSquare size={15} /> 消息

frontend/components/MessagesPolicyProvider.tsx

@@ -0,0 +1,52 @@
+"use client";
+
+import {
+  createContext,
+  useContext,
+  useEffect,
+  useRef,
+  useState,
+  type ReactNode,
+} from "react";
+import { useRouter } from "next/navigation";
+import { realtime, RT_SETTINGS_CHANGED, type RtSettingsData } from "@/lib/realtime";
+
+const AllowMessagesContext = createContext(true);
+
+/** 前台是否开放私聊/群聊（SSR 初值 + 后台开关热更新） */
+export function useAllowMessages(): boolean {
+  return useContext(AllowMessagesContext);
+}
+
+/**
+ * 根布局注入：关闭消息后前台立即隐藏入口；开启则刷新以拉回会话。
+ */
+export default function MessagesPolicyProvider({
+  allowMessages,
+  children,
+}: {
+  allowMessages: boolean;
+  children: ReactNode;
+}) {
+  const router = useRouter();
+  const [open, setOpen] = useState(allowMessages);
+  const openRef = useRef(open);
+  openRef.current = open;
+
+  useEffect(() => {
+    setOpen(allowMessages);
+  }, [allowMessages]);
+
+  useEffect(() => {
+    return realtime.on<RtSettingsData>(RT_SETTINGS_CHANGED, (data) => {
+      if (typeof data?.allow_messages !== "boolean") return;
+      if (openRef.current === data.allow_messages) return;
+      setOpen(data.allow_messages);
+      router.refresh();
+    });
+  }, [router]);
+
+  return (
+    <AllowMessagesContext.Provider value={open}>{children}</AllowMessagesContext.Provider>
+  );
+}

frontend/components/MessagesUnsupported.tsx

@@ -0,0 +1,29 @@
+import Link from "next/link";
+import { MessageSquareOff } from "lucide-react";
+
+/** 全站关闭消息时的前台说明：表达「不支持」而非暂时关闭。 */
+export default function MessagesUnsupported() {
+  return (
+    <div className="max-w-md mx-auto text-center py-16 sm:py-24">
+      <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>
+      <h1 className="text-[17px] font-semibold" style={{ color: "var(--ink)" }}>
+        本站不支持消息
+      </h1>
+      <p className="meta mt-1.5 text-[12.5px] leading-relaxed">
+        站点未提供私聊与群聊功能。
+      </p>
+      <Link href="/" className="btn btn-line btn-sm mt-5 inline-flex">
+        返回首页
+      </Link>
+    </div>
+  );
+}

frontend/lib/api.ts

@@ -596,6 +596,8 @@ export interface PublicSettings {
   allow_register: boolean;
   /** 全站是否开放评论；关闭后前台不展示评论能力 */
   allow_comments: boolean;
+  /** 全站是否开放私聊/群聊；关闭后前台不展示消息入口 */
+  allow_messages: boolean;
   post_cooldown_hours: number;
   /** 超过 N 行的代码块是否默认折叠；缺省 true */
   code_block_auto_fold: boolean;
@@ -620,6 +622,7 @@ const DEFAULT_PUBLIC_SETTINGS: PublicSettings = {
   site_description: "姜十三论坛 - 技术分享与讨论社区",
   allow_register: true,
   allow_comments: true,
+  allow_messages: true,
   post_cooldown_hours: 24,
   code_block_auto_fold: true,
   code_block_fold_lines: 5,
@@ -641,6 +644,7 @@ function normalizePublicSettings(data: Partial<PublicSettings> | null | undefine
         : DEFAULT_PUBLIC_SETTINGS.site_description,
     allow_register: data?.allow_register !== false,
     allow_comments: data?.allow_comments !== false,
+    allow_messages: data?.allow_messages !== false,
     post_cooldown_hours:
       typeof data?.post_cooldown_hours === "number" && data.post_cooldown_hours >= 0
         ? data.post_cooldown_hours
@@ -1744,6 +1748,7 @@ export type UpdateSiteSettingsBody = {
   site_description?: string;
   allow_register?: boolean;
   allow_comments?: boolean;
+  allow_messages?: boolean;
   post_cooldown_hours?: number;
   code_block_auto_fold?: boolean;
   code_block_fold_lines?: number;

frontend/lib/realtime.ts

@@ -45,6 +45,7 @@ export interface RtSettingsData {
   site_description?: string;
   allow_register?: boolean;
   allow_comments?: boolean;
+  allow_messages?: boolean;
   post_cooldown_hours?: number;
   code_block_auto_fold?: boolean;
   code_block_fold_lines?: number;