fix(frontend): 修复移动端菜单栏和使用记录页面 UI 问题

- 修复移动端无法打开菜单栏的问题
  - 在 app.ts 中添加 mobileOpen 状态管理
  - 修复 AppHeader.vue 中移动端菜单按钮调用错误的方法
  - 修复 AppSidebar.vue 使用本地 ref 而非全局状态的问题

- 添加移动端菜单自动关闭功能
  - 点击菜单项后自动关闭侧边栏
  - 添加 150ms 延迟以显示关闭动画

- 修复使用记录页面总消费卡片溢出问题
  - 调整总消费卡片布局，将删除线价格移至说明行
  - 添加 min-w-0 flex-1 防止内容溢出
  - 保持与其他卡片高度一致

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/src/stores/app.ts

@@ -12,6 +12,7 @@ export const useAppStore = defineStore('app', () => {
   // ==================== State ====================
 
   const sidebarCollapsed = ref<boolean>(false);
+  const mobileOpen = ref<boolean>(false);
   const loading = ref<boolean>(false);
   const toasts = ref<Toast[]>([]);
 
@@ -50,6 +51,21 @@ export const useAppStore = defineStore('app', () => {
     sidebarCollapsed.value = collapsed;
   }
 
+  /**
+   * Toggle mobile sidebar open state
+   */
+  function toggleMobileSidebar(): void {
+    mobileOpen.value = !mobileOpen.value;
+  }
+
+  /**
+   * Set mobile sidebar open state explicitly
+   * @param open - Whether mobile sidebar should be open
+   */
+  function setMobileOpen(open: boolean): void {
+    mobileOpen.value = open;
+  }
+
   /**
    * Set global loading state
    * @param isLoading - Whether app is in loading state
@@ -257,6 +273,7 @@ export const useAppStore = defineStore('app', () => {
   return {
     // State
     sidebarCollapsed,
+    mobileOpen,
     loading,
     toasts,
 
@@ -275,6 +292,8 @@ export const useAppStore = defineStore('app', () => {
     // Actions
     toggleSidebar,
     setSidebarCollapsed,
+    toggleMobileSidebar,
+    setMobileOpen,
     setLoading,
     showToast,
     showSuccess,