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/account/ModelWhitelistSelector.vue

@@ -21,9 +21,7 @@
               @click.stop="removeModel(model)"
               class="shrink-0 rounded-full hover:bg-gray-200 dark:hover:bg-dark-500"
             >
-              <svg class="h-3.5 w-3.5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
-                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12" />
-              </svg>
+              <Icon name="x" size="xs" class="h-3.5 w-3.5" :stroke-width="2" />
             </button>
           </span>
         </div>
@@ -126,6 +124,7 @@ import { ref, computed } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useAppStore } from '@/stores/app'
 import ModelIcon from '@/components/common/ModelIcon.vue'
+import Icon from '@/components/icons/Icon.vue'
 import { allModels, getModelsByPlatform } from '@/composables/useModelWhitelist'
 
 const { t } = useI18n()