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/chat/[id]/page.tsx

@@ -88,6 +88,7 @@ export default async function ChatRoomPage({ params }: PageProps) {
         peer={room.peer || null}
         meId={me.user.id}
         meRole={me.user.role}
+        canManageMessages={!!me.user.can_manage_messages}
         meName={me.user.nickname || me.user.username}
         meAvatar={me.user.avatar || ""}
         initialMessages={initialMessages.messages}