前端文案挑选页按 A/B/C 三套分组展示

- 后端 _fmt_text 返回 strategy 字段,SSE 与 hydrate 两条路径贯通
- 新建 TextStrategyGroup 组件 + groupByStrategy(A/B/C/未分套排序,旧 NULL 数据归未分套)
- text 页平铺改分组渲染,选中态/改稿回调透传不变
- 复用 ImageStrategyGroup 的 STRATEGY_LABEL,单向依赖无环

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/app/tasks/[id]/text/page.tsx

@@ -4,7 +4,8 @@ import { useEffect } from 'react';
 import { useRouter, useParams } from 'next/navigation';
 import { ProgressBar } from '@/components/layout/ProgressBar';
 import { FlywheelBannerFromSse } from '@/components/FlywheelBanner';
-import { TextCandidateCard, TextCandidateCardSkeleton } from '@/components/tasks/TextCandidateCard';
+import { TextCandidateCardSkeleton } from '@/components/tasks/TextCandidateCard';
+import { TextStrategyGroup, groupByStrategy } from '@/components/tasks/TextStrategyGroup';
 import { SseStatusBar } from '@/components/tasks/SseStatusBar';
 import { FatalErrorBanner } from '@/components/tasks/FatalErrorBanner';
 import { RejectReasonBanner } from '@/components/tasks/RejectReasonBanner';
@@ -73,20 +74,23 @@ export default function TextSelectionPage() {
           </div>
         )}
 
-        {/* 文案卡网格（谁好谁先冒） */}
-        <div className="grid grid-cols-2 xl:grid-cols-3 gap-4">
-          {showSkeleton
-            ? Array.from({ length: 4 }).map((_, i) => <TextCandidateCardSkeleton key={i} />)
-            : textCandidates.map((c) => (
-                <TextCandidateCard
-                  key={c.candidate_id}
-                  candidate={c}
-                  selected={selectedTextIds.includes(c.candidate_id)}
-                  onToggle={toggleTextSelection}
-                  onSaveEdit={handleSaveEdit}
-                />
-              ))}
-        </div>
+        {/* 文案卡：按 A/B/C 三套分组展示（让运营一眼看出三套不同角度）；生成中显示骨架 */}
+        {showSkeleton ? (
+          <div className="grid grid-cols-2 xl:grid-cols-3 gap-4">
+            {Array.from({ length: 4 }).map((_, i) => <TextCandidateCardSkeleton key={i} />)}
+          </div>
+        ) : (
+          groupByStrategy(textCandidates).map(([strategy, list]) => (
+            <TextStrategyGroup
+              key={strategy}
+              strategy={strategy}
+              candidates={list}
+              selectedTextIds={selectedTextIds}
+              onToggle={toggleTextSelection}
+              onSaveEdit={handleSaveEdit}
+            />
+          ))
+        )}
 
         {/* 底部操作栏 */}
         {textCandidates.length > 0 && (