feat: 内测申请弹窗 + 电商功能介绍页样式优化

- 新增 BetaApplicationModal 组件，支持文本输入、单/多选、签字等交互

- 顶部通知铃铛左侧添加「内测申请」按钮（脉冲动画）

- 电商功能介绍页等比例放大，减少空白，布局更紧凑

- 右侧卡片区域放大，卡片内容清晰可见

src/features/ecommerce/EcommercePage.tsx

@@ -839,6 +839,7 @@ function ProductClonePage(_props: ProductClonePageProps = {}) {
   const skipInitialCloneAutoSaveRef = useRef(true);
   const skipNextCloneAutoSaveRef = useRef(false);
   const [activeTool, setActiveTool] = useState<ProductKitToolKey>("clone");
+  useEffect(() => { setPreviewZoom(1); }, [activeTool]);
   const [setImages, setSetImages] = useState<CloneImageItem[]>([]);
   const [productSetPlatform, setProductSetPlatform] = useState(platformOptions[0]);
   const [productSetMarket, setProductSetMarket] = useState(marketOptions[0]);
@@ -879,6 +880,30 @@ function ProductClonePage(_props: ProductClonePageProps = {}) {
   const [videoOutfitRefFile, setVideoOutfitRefFile] = useState<File | null>(null);
   const [isCloneSettingsCollapsed, setIsCloneSettingsCollapsed] = useState(false);
   const [previewZoom, setPreviewZoom] = useState(1);
+
+  const handlePreviewWheel = (event: React.WheelEvent<HTMLElement>) => {
+    if (!event.currentTarget) return;
+    event.preventDefault();
+    const container = event.currentTarget as HTMLElement;
+    const rect = container.getBoundingClientRect();
+    const cursorX = event.clientX - rect.left;
+    const cursorY = event.clientY - rect.top;
+    const zoomDelta = event.deltaY < 0 ? 1.08 : 0.92;
+
+    const nextZoom = Math.min(2, Math.max(0.25, previewZoom * zoomDelta));
+    if (nextZoom === previewZoom) return;
+
+    const contentX = (cursorX + container.scrollLeft) / previewZoom;
+    const contentY = (cursorY + container.scrollTop) / previewZoom;
+
+    setPreviewZoom(nextZoom);
+
+    requestAnimationFrame(() => {
+      container.scrollLeft = contentX * nextZoom - cursorX;
+      container.scrollTop = contentY * nextZoom - cursorY;
+    });
+  };
+
   const [requirement, setRequirement] = useState("");
   const [requirementImageMentionQuery, setRequirementImageMentionQuery] = useState<string | null>(null);
   const [cloneSettingName, setCloneSettingName] = useState("新建创作");
@@ -2251,7 +2276,7 @@ function ProductClonePage(_props: ProductClonePageProps = {}) {
   );
 
   const setPreview = (
-    <main className="product-clone-preview product-clone-preview--set" aria-label="AI商品套图预览">
+    <main className="product-clone-preview product-clone-preview--set" aria-label="AI商品套图预览" onWheel={handlePreviewWheel}>
       <div className="product-clone-preview__headline">
         <h1>预览</h1>
         <p>
@@ -2319,7 +2344,7 @@ function ProductClonePage(_props: ProductClonePageProps = {}) {
   );
 
   const clonePreview = (
-    <main className="product-clone-preview clone-ai-preview" aria-label="电商AI作图预览">
+    <main className="product-clone-preview clone-ai-preview" aria-label="电商AI作图预览" onWheel={handlePreviewWheel}>
       <header className="clone-ai-preview-header">
         <strong>预览</strong>
         <span>
@@ -2529,7 +2554,7 @@ function ProductClonePage(_props: ProductClonePageProps = {}) {
   );
 
   const detailPreview = (
-    <main className="product-clone-preview product-clone-preview--detail" aria-label="A+详情预览">
+    <main className="product-clone-preview product-clone-preview--detail" aria-label="A+详情预览" onWheel={handlePreviewWheel}>
       <div className="product-clone-preview__headline">
         <h1>A+/详情页</h1>
         <p>
@@ -2566,7 +2591,7 @@ function ProductClonePage(_props: ProductClonePageProps = {}) {
   );
 
   const tryOnPreview = (
-    <main className="product-clone-preview product-clone-preview--try-on" aria-label="服饰穿戴预览">
+    <main className="product-clone-preview product-clone-preview--try-on" aria-label="服饰穿戴预览" onWheel={handlePreviewWheel}>
       <div className="product-clone-preview__headline">
         <h1>AI服饰穿戴</h1>
         <p>上传服装图，定制专属模特，即刻生成多种场景不同姿势套图。</p>