feat: 导航/侧边栏菜单脱敏 + 圆桌会商各步输入框自适应高度

- 菜单标签展示层脱敏：useSidebarMenuItems 直接用 /api/sensitive-words
  结果构造脱敏器，覆盖导航栏/三套侧边栏皮肤/三级子导航；菜单管理页用原始树不受影响
- 新增可复用 AutoGrowTextarea（自适应高度多行框），替换圆桌 Step1/2/3 输入框：
  多行时自动扩展、到上限框内滚动；Step2 两个单行 input 改多行；统一 Enter 发送/Shift+Enter 换行
- 各步输入框最大展开高度翻倍（Step1 320 / Step2 280 / Step3 224）

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

frontend-web/src/roundtable-planning/components/Step3DashboardMode.tsx

@@ -35,6 +35,7 @@ import {
 } from "lucide-react";
 
 import { useLocalSettings } from "@/core/settings";
+import { AutoGrowTextarea } from "@/components/ui/auto-grow-textarea";
 import { desensitizeDeep } from "@/lib/desensitize";
 import type { DraftStep3Snapshot } from "@/roundtable-planning/api/drafts";
 import { DashboardApp } from "@/roundtable-planning/dashboard/DashboardApp";
@@ -545,7 +546,8 @@ function DashboardChatPanel({
         {/* 问答修改输入框 */}
         <form onSubmit={handleSubmit} className="shrink-0 border-t border-slate-100 bg-white px-3 py-3">
           <div className="flex items-end gap-2 rounded-2xl border border-slate-200 bg-slate-50/70 px-3 py-2 focus-within:border-primary/60 focus-within:bg-white focus-within:ring-2 focus-within:ring-[var(--brand-200)]/40">
-            <textarea
+            <AutoGrowTextarea
+              maxHeight={224}
               value={text}
               onChange={(e) => setText(e.target.value)}
               onKeyDown={(e) => {
@@ -561,7 +563,7 @@ function DashboardChatPanel({
                   ? "随时输入修改要求——发送会打断当前绘制并按新要求重出数据"
                   : "输入修改要求，例如：把风险分布换成柱状图，新增一个执行路线席位"
               }
-              className="min-h-8 max-h-28 flex-1 resize-none bg-transparent py-1.5 text-xs leading-relaxed text-slate-800 placeholder:text-slate-400 focus:outline-none disabled:cursor-not-allowed disabled:opacity-60"
+              className="min-h-8 max-h-56 flex-1 resize-none bg-transparent py-1.5 text-xs leading-relaxed text-slate-800 placeholder:text-slate-400 focus:outline-none disabled:cursor-not-allowed disabled:opacity-60"
             />
             <button
               type="submit"