feat: 完全移除 API Key 图标功能

彻底删除 API Key 图标功能的所有相关代码：

前端改动：
- 删除 IconPicker.vue 组件文件
- 移除 ApiKeysView.vue 中的图标显示和 updateApiKeyIcon 方法
- 清理 CreateApiKeyModal.vue 中的图标选择器
- 清理 EditApiKeyModal.vue 中的图标选择器
- 移除所有 IconPicker 组件的引用

后端改动：
- 从 apiKeyService.js 中移除 icon 字段更新支持
- 从 admin.js 路由中移除 icon 参数处理和验证逻辑
- 清理创建和更新 API Key 时的 icon 参数

此改动简化了 API Key 管理界面，移除了不必要的图标功能。

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

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

web/admin-spa/src/components/apikeys/CreateApiKeyModal.vue

@@ -110,9 +110,7 @@
               class="mb-1.5 block text-xs font-semibold text-gray-700 dark:text-gray-300 sm:mb-2 sm:text-sm"
               >名称 <span class="text-red-500">*</span></label
             >
-            <div class="flex items-center gap-2">
-              <!-- 图标选择器 -->
-              <IconPicker v-model="form.icon" size="medium" />
+            <div>
               <input
                 v-model="form.name"
                 class="form-input flex-1 border-gray-300 text-sm dark:border-gray-600 dark:bg-gray-700 dark:text-gray-200 dark:placeholder-gray-400"
@@ -811,7 +809,6 @@ import { useClientsStore } from '@/stores/clients'
 import { useApiKeysStore } from '@/stores/apiKeys'
 import { apiClient } from '@/config/api'
 import AccountSelector from '@/components/common/AccountSelector.vue'
-import IconPicker from '@/components/common/IconPicker.vue'
 
 const props = defineProps({
   accounts: {
@@ -858,7 +855,6 @@ const form = reactive({
   createType: 'single',
   batchCount: 10,
   name: '',
-  icon: '',
   description: '',
   rateLimitWindow: '',
   rateLimitRequests: '',
@@ -1204,8 +1200,7 @@ const createApiKey = async () => {
       // 单个创建
       const data = {
         ...baseData,
-        name: form.name,
-        icon: form.icon || ''
+        name: form.name
       }
 
       const result = await apiClient.post('/admin/api-keys', data)
@@ -1223,8 +1218,7 @@ const createApiKey = async () => {
         ...baseData,
         createType: 'batch',
         baseName: form.name,
-        count: form.batchCount,
-        icon: form.icon || ''
+        count: form.batchCount
       }
 
       const result = await apiClient.post('/admin/api-keys/batch', data)