✨ feat(ui): 调整轮播间隔并优化管理后台菜单按钮

- 将小程序首页轮播图自动播放间隔从4000ms缩短至3000ms以提升用户体验
- 统一管理后台布局的菜单按钮，移除重复的桌面端按钮，将移动端按钮文本设为“菜单栏”并调整尺寸

mini/src/pages/index/index.tsx

@@ -424,7 +424,7 @@ const HomePage: React.FC = () => {
                   }))}
                   height={800}
                   autoplay={true}
-                  interval={4000}
+                  interval={3000}
                   circular={true}
                   imageMode="aspectFit"
                 />

web/src/client/admin/layouts/MainLayout.tsx

@@ -168,20 +168,12 @@ export const MainLayout = () => {
           <div className="flex items-center gap-2">
             <Button
               variant="ghost"
-              size="icon"
-              className="md:hidden"
+              size="sm" 
               onClick={() => setIsMobileMenuOpen(true)}
               data-testid="mobile-menu-button"
             >
               <Menu className="h-4 w-4" />
-            </Button>
-            <Button
-              variant="ghost"
-              size="icon"
-              className="hidden md:block"
-              onClick={() => setCollapsed(!collapsed)}
-            >
-              <Menu className="h-4 w-4" />
+              菜单栏
             </Button>
           </div>