继续收口生成页顶部返回按钮

抽出生成页共用返回按钮壳并复用共享图标按钮能力
将自定义世界生成页接入共享返回按钮壳
将汪汪声浪生成页接入共享返回按钮壳并保留禁用态
补充两个生成页返回按钮的样式与交互回归测试

src/components/GenerationProgressHero.tsx

@@ -1,7 +1,8 @@
-import { Clock3, Hourglass } from 'lucide-react';
+import { ArrowLeft, Clock3, Hourglass } from 'lucide-react';
 import { useEffect, useId, useRef } from 'react';
 
 import generationHeroVideo from '../../media/create_bg_video.mp4';
+import { PlatformIconButton } from './common/PlatformIconButton';
 import { PlatformProgressBar } from './common/PlatformProgressBar';
 
 const GENERATION_PROGRESS_RING_GAP_DEGREES = 90;
@@ -35,6 +36,14 @@ type GenerationCurrentStepCardProps = {
   progressValue: number;
 };
 
+type GenerationHeaderBackButtonProps = {
+  label: string;
+  onClick: () => void;
+  disabled?: boolean;
+  disabledOpacity?: number;
+  className?: string;
+};
+
 function clampGenerationProgress(value: number) {
   return Math.max(0, Math.min(100, Math.round(value)));
 }
@@ -51,6 +60,34 @@ function buildGenerationRingMetrics(progressValue: number) {
   };
 }
 
+export function GenerationHeaderBackButton({
+  label,
+  onClick,
+  disabled = false,
+  disabledOpacity,
+  className,
+}: GenerationHeaderBackButtonProps) {
+  return (
+    <PlatformIconButton
+      label={label}
+      title={label}
+      variant="darkMini"
+      onClick={onClick}
+      disabled={disabled}
+      className={[
+        'gap-2 rounded-full !border-transparent !bg-transparent px-0 py-2 text-xs font-black !text-[#171411] shadow-none hover:!bg-transparent hover:!text-[#171411] sm:text-sm',
+        className,
+      ]
+        .filter(Boolean)
+        .join(' ')}
+      style={disabled && disabledOpacity != null ? { opacity: disabledOpacity } : undefined}
+      icon={<ArrowLeft className="h-5 w-5 shrink-0" strokeWidth={2.6} />}
+    >
+      <span className="break-keep">{label}</span>
+    </PlatformIconButton>
+  );
+}
+
 export function GenerationPageBackdrop() {
   const videoRef = useRef<HTMLVideoElement | null>(null);