继续收口浅色返回按钮

将统一创作页与多个浅色工作台返回入口切换为 PlatformBackActionButton
按页面保留 compact 与 regular 返回尺寸及禁用态
清理冗余 ArrowLeft 引用并完成对应页面定向验证

src/components/creative-agent/CreativeAgentWorkspace.tsx

@@ -1,4 +1,4 @@
-import { ArrowLeft, CheckCircle2, Puzzle } from 'lucide-react';
+import { CheckCircle2, Puzzle } from 'lucide-react';
 import { useEffect, useMemo, useState } from 'react';
 
 import type {
@@ -11,6 +11,7 @@ import type {
   PuzzleCreativeTemplateSelection,
 } from '../../../packages/shared/src/contracts/puzzleCreativeTemplate';
 import { PlatformActionButton } from '../common/PlatformActionButton';
+import { PlatformBackActionButton } from '../common/PlatformBackActionButton';
 import { PlatformEmptyState } from '../common/PlatformEmptyState';
 import { PlatformIconBadge } from '../common/PlatformIconBadge';
 import { PlatformMediaFrame } from '../common/PlatformMediaFrame';
@@ -149,18 +150,11 @@ export function CreativeAgentWorkspace({
     <div className="platform-remap-surface mx-auto flex h-full min-h-0 w-full flex-col xl:max-w-[min(100%,88rem)] xl:px-1">
       <div className="mb-3 flex items-center justify-between gap-3">
         {showBackButton ? (
-          <PlatformActionButton
-            tone="ghost"
-            size="xs"
+          <PlatformBackActionButton
             onClick={onBack}
             disabled={isBusy}
-            className="min-h-0 px-3 py-1.5 text-[11px]"
-          >
-            <span className="inline-flex items-center gap-1.5">
-              <ArrowLeft className="h-3.5 w-3.5" />
-              返回
-            </span>
-          </PlatformActionButton>
+            className="px-3"
+          />
         ) : (
           <span aria-hidden="true" />
         )}