💄 style(layout): adjust mobile menu button position

- change top position from top-6 to top-12
- change right position from right-6 to right-2

src/client/mobile/layouts/MainLayout.tsx

@@ -153,7 +153,7 @@ export const MainLayout = () => {
       {/* 浮动菜单按钮 - 移动端 */}
       <button
         onClick={() => setSidebarOpen(true)}
-        className="lg:hidden fixed top-6 right-6 z-50 w-10 h-10 rounded-full bg-primary text-primary-foreground flex items-center justify-center shadow-lg hover:bg-primary/90 transition-colors"
+        className="lg:hidden fixed top-12 right-2 z-50 w-10 h-10 rounded-full bg-primary text-primary-foreground flex items-center justify-center shadow-lg hover:bg-primary/90 transition-colors"
       >
         <Menu className="w-5 h-5" />
       </button>