feat(website): 添加虾盘 U-Claw 购买按钮和 MiniPC 即将推出按钮

Hero 区域和底部 CTA 区域各加两个按钮：
- 购买虾盘 U-Claw：绿色边框，跳转到联系区域
- 虾盘 MiniPC（即将推出）：灰色不可点击
- 联系区域添加 id="contact" 锚点

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

website/index.html

@@ -348,6 +348,14 @@
             <span class="zh">🖥️ 远程控制</span>
             <span class="en hidden">🖥️ Remote Control</span>
         </a>
+        <a href="#contact" class="btn btn-outline" style="border-color:var(--green);color:var(--green);">
+            <span class="zh">🛒 购买虾盘 U-Claw</span>
+            <span class="en hidden">🛒 Buy U-Claw USB</span>
+        </a>
+        <a href="#" class="btn btn-outline" style="opacity:0.5;cursor:not-allowed;" onclick="return false;">
+            <span class="zh">🖥 虾盘 MiniPC（即将推出）</span>
+            <span class="en hidden">🖥 MiniPC (Coming Soon)</span>
+        </a>
     </div>
 
     <div class="stats">
@@ -649,11 +657,19 @@
             <span class="zh">📖 查看文档</span>
             <span class="en hidden">📖 Documentation</span>
         </a>
+        <a href="#contact" class="btn btn-outline" style="border-color:var(--green);color:var(--green);">
+            <span class="zh">🛒 购买虾盘 U-Claw</span>
+            <span class="en hidden">🛒 Buy U-Claw USB</span>
+        </a>
+        <a href="#" class="btn btn-outline" style="opacity:0.5;cursor:not-allowed;" onclick="return false;">
+            <span class="zh">🖥 虾盘 MiniPC（即将推出）</span>
+            <span class="en hidden">🖥 MiniPC (Coming Soon)</span>
+        </a>
     </div>
 </div>
 
 <!-- Contact -->
-<section>
+<section id="contact">
     <h2>
         <span class="zh">联系我们</span>
         <span class="en hidden">Contact</span>