feat(ui): 将选择组件替换为组合框以支持搜索功能

将 StyleSelector 和 TextGeneratePopup 中的 Select 组件替换为 Combobox 组件，添加搜索过滤功能。

- StyleSelector.vue: 将 Select 组件替换为 Combobox，添加搜索关键词过滤和显示值处理
- TextGeneratePopup.vue: 将智能体选择器从 Select 升级为 Combobox，支持按名称搜索智能体
- 两个组件都添加了搜索输入框、过滤逻辑和空状态显示

frontend/app/web-gold/src/components/StyleSelector.vue

@@ -1,11 +1,18 @@
 <template>
-  <Select v-model="selectedId" @update:model-value="handleChange">
-    <SelectTrigger class="w-full">
-      <SelectValue :placeholder="placeholder" />
-    </SelectTrigger>
-    <SelectContent>
-      <SelectItem
-        v-for="item in allList"
+  <Combobox v-model="selectedId" @update:model-value="handleChange">
+    <ComboboxAnchor class="w-full">
+      <ComboboxTrigger as-child>
+        <ComboboxInput
+          :placeholder="placeholder"
+          v-model="searchKeyword"
+          :display-value="displayValue"
+        />
+      </ComboboxTrigger>
+    </ComboboxAnchor>
+    <ComboboxList>
+      <ComboboxEmpty>未找到匹配项</ComboboxEmpty>
+      <ComboboxItem
+        v-for="item in filteredList"
         :key="item.id"
         :value="item.id"
       >
@@ -14,14 +21,9 @@
           <span class="option-name">{{ item.name }}</span>
           <span class="option-tag">{{ item.category || '其他' }}</span>
         </div>
-      </SelectItem>
-
-      <!-- 空状态 -->
-      <div v-if="!loading && allList.length === 0" class="empty-text">
-        暂无可选项
-      </div>
-    </SelectContent>
-  </Select>
+      </ComboboxItem>
+    </ComboboxList>
+  </Combobox>
 </template>
 
 <script setup>
@@ -29,7 +31,15 @@ import { ref, computed, watch, onMounted } from 'vue'
 import { usePromptStore } from '@/stores/prompt'
 import { getJSON, setJSON } from '@/utils/storage'
 
-import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
+import {
+  Combobox,
+  ComboboxAnchor,
+  ComboboxEmpty,
+  ComboboxInput,
+  ComboboxItem,
+  ComboboxList,
+  ComboboxTrigger
+} from '@/components/ui/combobox'
 
 const props = defineProps({
   modelValue: {
@@ -52,10 +62,30 @@ const promptStore = usePromptStore()
 
 const loading = ref(false)
 const selectedId = ref(null)
+const searchKeyword = ref('')
 
 // 全部列表（来自 /ai/user-prompt/my-list）
 const allList = computed(() => promptStore.promptList || [])
 
+// 过滤后的列表
+const filteredList = computed(() => {
+  if (!searchKeyword.value.trim()) {
+    return allList.value
+  }
+  const keyword = searchKeyword.value.toLowerCase()
+  return allList.value.filter(item =>
+    item.name?.toLowerCase().includes(keyword) ||
+    item.category?.toLowerCase().includes(keyword)
+  )
+})
+
+// 显示选中项名称
+const displayValue = (val) => {
+  if (!val) return ''
+  const item = allList.value.find(p => p.id === val)
+  return item?.name || ''
+}
+
 // 处理选择变化
 function handleChange(value) {
   if (!value) {