完善角色与消息权限：收紧板管内容处置，彻底删除仅站长，并统一管理删帖/评弹窗。

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

frontend/app/admin/messages/MessagesAdmin.tsx

@@ -14,8 +14,10 @@ import {
   apiAdminRecallChatMessage,
   type AdminChatMessage,
   type AdminChatRoomType,
+  type User,
 } from "@/lib/api";
 import { formatRelative } from "@/lib/format";
+import { canOverseeChat } from "@/lib/roles";
 import { toast } from "@/lib/toast";
 import Avatar from "@/components/Avatar";
 import AutolinkText from "@/components/AutolinkText";
@@ -247,7 +249,8 @@ function useMessageColumn(roomType: MsgKind) {
 }
 
 /** 群聊（含大厅）| 私聊 双栏监管 */
-export default function MessagesAdmin() {
+export default function MessagesAdmin({ me }: { me: User }) {
+  const canOversee = canOverseeChat(me.role);
   const [mobileKind, setMobileKind] = useState<MsgKind>("group");
   const group = useMessageColumn("group");
   const direct = useMessageColumn("direct");
@@ -485,37 +488,43 @@ export default function MessagesAdmin() {
       <AdminPageHeader
         icon={MessagesSquare}
         title="消息管理"
-        description="分栏监管群聊与私聊；可搜索并撤回违规内容"
+        description={
+          canOversee
+            ? "分栏监管群聊与私聊；可搜索并撤回违规内容"
+            : "监管授权范围内的群聊消息；可搜索并撤回违规内容（不含私聊）"
+        }
       />
 
-      <div className="admin-content-kind lg:hidden shrink-0" role="tablist" aria-label="消息类型">
-        <button
-          type="button"
-          role="tab"
-          aria-selected={mobileKind === "group"}
-          className="admin-content-kind-btn"
-          onClick={() => setMobileKind("group")}
-        >
-          <Users size={14} aria-hidden />
-          群聊
-          <span className="admin-content-kind-count">{group.total}</span>
-        </button>
-        <button
-          type="button"
-          role="tab"
-          aria-selected={mobileKind === "direct"}
-          className="admin-content-kind-btn"
-          onClick={() => setMobileKind("direct")}
-        >
-          <MessageCircle size={14} aria-hidden />
-          私聊
-          <span className="admin-content-kind-count">{direct.total}</span>
-        </button>
-      </div>
+      {canOversee ? (
+        <div className="admin-content-kind lg:hidden shrink-0" role="tablist" aria-label="消息类型">
+          <button
+            type="button"
+            role="tab"
+            aria-selected={mobileKind === "group"}
+            className="admin-content-kind-btn"
+            onClick={() => setMobileKind("group")}
+          >
+            <Users size={14} aria-hidden />
+            群聊
+            <span className="admin-content-kind-count">{group.total}</span>
+          </button>
+          <button
+            type="button"
+            role="tab"
+            aria-selected={mobileKind === "direct"}
+            className="admin-content-kind-btn"
+            onClick={() => setMobileKind("direct")}
+          >
+            <MessageCircle size={14} aria-hidden />
+            私聊
+            <span className="admin-content-kind-count">{direct.total}</span>
+          </button>
+        </div>
+      ) : null}
 
-      <div className="admin-content-triptych">
+      <div className={canOversee ? "admin-content-triptych" : "admin-content-triptych admin-content-triptych--single"}>
         {groupCol}
-        {directCol}
+        {canOversee ? directCol : null}
       </div>
 
       <ConfirmDialog