refactor: 重构纹理图集工具，实现浏览器端实时处理

将合图处理从服务端迁移到浏览器端，使用 Web Worker 实现高性能打包算法，新增三栏布局界面和精灵动画预览功能

- 新增 atlasStore 状态管理，实现文件、配置、结果的统一管理
- 新增 atlas-packer 打包算法库（MaxRects/Shelf），支持浏览器端快速合图
- 新增 atlas-worker Web Worker，实现异步打包处理避免阻塞 UI
- 新增三栏布局组件：FileListPanel、CanvasPreview、AtlasConfigPanel
- 新增 AnimationPreviewDialog 支持精灵动画帧预览和帧率控制
- 优化所有工具页面的响应式布局和交互体验

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/components/layout/Footer.tsx

@@ -1,11 +1,14 @@
 "use client";
 
 import Link from "next/link";
+import { usePathname } from "next/navigation";
 import { Sparkles } from "lucide-react";
 import { useEffect, useMemo, useState } from "react";
 import { useTranslation, getServerTranslations } from "@/lib/i18n";
+import { cn } from "@/lib/utils";
 
 export function Footer() {
+  const pathname = usePathname();
   const [mounted, setMounted] = useState(false);
   const { t } = useTranslation();
 
@@ -26,8 +29,14 @@ export function Footer() {
     [mounted]
   );
 
+  // Check if we're in the dashboard area (tools pages)
+  const isDashboard = pathname?.startsWith("/tools");
+
   return (
-    <footer className="border-t border-white/5 bg-background/50">
+    <footer className={cn(
+      "border-t border-white/5 bg-background/50",
+      isDashboard && "lg:ml-64"
+    )}>
       <div className="container py-12">
         <div className="grid gap-10 md:grid-cols-[1.5fr_1fr]">
           <div>