feat(roundtable): 多智能体会商 + 业务链条页脱敏

- 区域级脱敏 Hook useDesensitizeSubtree：对左右侧面板、顶部标题、
  业务链条选择器/列表弹窗/列表页/配置页/映射页整片脱敏（文本节点，
  跳过 input/textarea 等可编辑控件）
- 消息列表正文保持原文，仅智能体名称脱敏（senderName / 席位名 / 流程图节点）
- Step3 总结/报告/大屏、推荐弹窗等结果面板脱敏
- 沙箱产物预览不脱敏：ArtifactFileDetail 加 disableDesensitize，会商沙箱传入
- desensitize.ts 新增 desensitizeDeep 递归脱敏结构化数据

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/roundtable-planning/components/Step3ReportMode.tsx

@@ -44,6 +44,7 @@ import { ConsensusDocxDownloadButton } from "@/roundtable-planning/components/Co
 import { ScrollToBottomButton } from "@/roundtable-planning/components/ScrollToBottomButton";
 import { Step2Message } from "@/roundtable-planning/components/Step2Panel";
 import { Step2SandboxLayout } from "@/roundtable-planning/components/Step2SandboxLayout";
+import { desensitize } from "@/lib/desensitize";
 import { markdownComponents } from "@/roundtable-planning/components/markdown-components";
 import type { DraftStep3Snapshot } from "@/roundtable-planning/api/drafts";
 import { Step3DashboardMode } from "@/roundtable-planning/components/Step3DashboardMode";
@@ -407,7 +408,7 @@ export function Step3ReportMode({
         >
           {consensusText ? (
             <ReactMarkdown remarkPlugins={[remarkGfm]} components={markdownComponents}>
-              {consensusText}
+              {desensitize(consensusText)}
             </ReactMarkdown>
           ) : (
             <p className="text-xs text-slate-400 italic">暂无总控结论。</p>
@@ -773,14 +774,14 @@ function SeatDeliveriesView({ seatDeliveries }: { seatDeliveries: SeatDelivery[]
             >
               <div className="flex items-center gap-2 min-w-0">
                 <ListOrdered className="w-3.5 h-3.5 text-slate-400 shrink-0" />
-                <span className="text-[11.5px] font-bold text-slate-800 truncate">{seat.sender}</span>
+                <span className="text-[11.5px] font-bold text-slate-800 truncate">{desensitize(seat.sender)}</span>
               </div>
               <span className="text-[10px] text-slate-400 font-mono shrink-0">{seat.content.length} 字</span>
             </button>
             {open && (
               <div className="px-4 py-3 text-xs text-slate-700 leading-relaxed border-t border-slate-100 bg-white">
                 <ReactMarkdown remarkPlugins={[remarkGfm]} components={markdownComponents}>
-                  {seat.content || "(空)"}
+                  {desensitize(seat.content || "(空)")}
                 </ReactMarkdown>
               </div>
             )}