refactor(frontend): 完成所有组件的内联SVG统一替换为Icon组件

- 扩展 Icon.vue 组件，新增 60+ 图标路径
  - 导航类: arrowRight, arrowLeft, arrowUp, arrowDown, chevronUp, externalLink
  - 状态类: checkCircle, xCircle, exclamationCircle, exclamationTriangle, infoCircle
  - 用户类: user, userCircle, userPlus, users
  - 文档类: document, clipboard, copy, inbox
  - 操作类: download, upload, filter, sort
  - 安全类: key, lock, shield
  - UI类: menu, calendar, home, terminal, gift, creditCard, mail
  - 数据类: chartBar, trendingUp, database, cube
  - 其他: bolt, sparkles, cloud, server, sun, moon, book 等

- 重构 56 个 Vue 组件，用 Icon 组件替换内联 SVG
  - 净减少约 2200 行代码
  - 提升代码可维护性和一致性
  - 统一图标样式和尺寸管理

frontend/src/components/user/dashboard/UserDashboardRecentUsage.vue

@@ -15,9 +15,7 @@
         <div v-for="log in data" :key="log.id" class="flex items-center justify-between rounded-xl bg-gray-50 p-4 transition-colors hover:bg-gray-100 dark:bg-dark-800/50 dark:hover:bg-dark-800">
           <div class="flex items-center gap-4">
             <div class="flex h-10 w-10 items-center justify-center rounded-xl bg-primary-100 dark:bg-primary-900/30">
-              <svg class="h-5 w-5 text-primary-600 dark:text-primary-400" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="1.5">
-                <path stroke-linecap="round" stroke-linejoin="round" d="M9.75 3.104v5.714a2.25 2.25 0 01-.659 1.591L5 14.5M9.75 3.104c-.251.023-.501.05-.75.082m.75-.082a24.301 24.301 0 014.5 0m0 0v5.714c0 .597.237 1.17.659 1.591L19.8 15.3M14.25 3.104c.251.023.501.05.75.082M19.8 15.3l-1.57.393A9.065 9.065 0 0112 15a9.065 9.065 0 00-6.23.693L5 14.5m14.8.8l1.402 1.402c1.232 1.232.65 3.318-1.067 3.611A48.309 48.309 0 0112 21c-2.773 0-5.491-.235-8.135-.687-1.718-.293-2.3-2.379-1.067-3.61L5 14.5" />
-              </svg>
+              <Icon name="beaker" size="md" class="text-primary-600 dark:text-primary-400" />
             </div>
             <div>
               <p class="text-sm font-medium text-gray-900 dark:text-white">{{ log.model }}</p>
@@ -35,9 +33,7 @@
 
         <router-link to="/usage" class="flex items-center justify-center gap-2 py-3 text-sm font-medium text-primary-600 transition-colors hover:text-primary-700 dark:text-primary-400 dark:hover:text-primary-300">
           {{ t('dashboard.viewAllUsage') }}
-          <svg class="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="1.5">
-            <path stroke-linecap="round" stroke-linejoin="round" d="M13.5 4.5L21 12m0 0l-7.5 7.5M21 12H3" />
-          </svg>
+          <Icon name="arrowRight" size="sm" />
         </router-link>
       </div>
     </div>
@@ -48,6 +44,7 @@
 import { useI18n } from 'vue-i18n'
 import LoadingSpinner from '@/components/common/LoadingSpinner.vue'
 import EmptyState from '@/components/common/EmptyState.vue'
+import Icon from '@/components/icons/Icon.vue'
 import { formatDateTime } from '@/utils/format'
 import type { UsageLog } from '@/types'