feat: refresh product website experience

The website previously buried platform downloads and presented the desktop assistant, Agent Runtime, and broader work capabilities with competing priorities. It now leads with the desktop assistant and AI programming workbench positioning, surfaces cross-platform and domestic Linux compatibility, and uses a responsive interactive product preview with synchronized tilt and soft lighting.

Release note: GoodBuddy 官网现在更清晰地展示桌面助手、Agent Runtime、跨平台与国产化支持，并提供更直观的动态产品预览。

sites/scripts/validate.mjs

@@ -67,22 +67,37 @@ report(/class="skip-link"\s+href="#main-content"/.test(html), "缺少跳到主
 report(/<main\s+id="main-content">/.test(html), "缺少 main-content 主区域");
 report(/aria-label="主导航"/.test(html), "主导航缺少可访问名称");
 report(/data-theme-toggle/.test(html), "缺少主题切换控件");
+report(/data-tilt-stage/.test(html), "首屏产品界面缺少倾斜交互区域");
+report(/data-tilt-card/.test(html), "首屏产品界面缺少倾斜卡片");
 report(/prefers-reduced-motion:\s*reduce/.test(css), "缺少减少动态效果规则");
 report(/\[data-theme="dark"\]/.test(css), "缺少深色主题令牌");
+report(/--scene-tilt-x/.test(css), "缺少产品界面横向倾斜变量");
+report(/--spotlight-x/.test(css), "缺少产品界面动态光效变量");
+report(
+  /\.floating-card[\s\S]*rotateX\(var\(--scene-tilt-x\)\)/.test(css),
+  "浮动标签必须跟随产品界面倾斜",
+);
+report(/requestAnimationFrame/.test(appJs), "产品界面倾斜交互必须按帧更新");
 
 for (const breakpoint of ["1199px", "959px", "719px"]) {
   report(css.includes(`max-width: ${breakpoint}`), `缺少 ${breakpoint} 响应式断点`);
 }
 
 const requiredCopy = [
-  "在本地管理笔记和待办",
+  "桌面助手",
+  "AI 编程工具台",
+  "Windows、macOS、Linux",
+  "统信 UOS",
+  "银河麒麟",
+  "海光 · 兆芯（x64）",
+  "鲲鹏 · 飞腾（ARM64）",
+  "独创的统一 Agent Runtime",
+  "直连模型、OpenCode、Continue",
+  "DeepSeek Harness",
+  "魔法笔记",
+  "智能心跳",
+  "文件、截图、应用窗口、剪贴板和离线语音",
   "微信、企业微信和钉钉",
-  "单条消息最多 4 个附件",
-  "OpenCode 与 Continue",
-  "单次最多添加 8 个附件，支持同时传入 5 张图片",
-  "auto、low、medium、high",
-  "下载入口始终指向最新正式 Release",
-  "主要安全边界",
 ];
 
 for (const copy of requiredCopy) {
@@ -98,7 +113,7 @@ report(
 const releaseLinks = [
   ...html.matchAll(/<a\b(?=[^>]*data-release-link)[^>]*>/g),
 ].map((match) => match[0]);
-report(releaseLinks.length >= 5, "缺少完整的官方下载入口");
+report(releaseLinks.length >= 3, "缺少三个桌面系统的官方下载入口");
 for (const link of releaseLinks) {
   report(
     /href="https:\/\/github\.com\/mesalogo\/goodbuddy\/releases\/latest"/.test(link),