refactor: 范式分段写作页面下拉框支持图标渲染

- 用自定义下拉组件替代原生 select (原生不支持渲染组件)
- 添加下拉框控制逻辑和点击外部关闭功能
- 添加自定义下拉框 CSS 样式

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

src/components/ParadigmWriterPanel.vue

@@ -14,20 +14,27 @@
         <!-- 1. 选择范式 -->
         <section class="writer-section">
           <label class="writer-label">1. 选择写作范式</label>
-          <select 
-            v-model="selectedParadigmId" 
-            @change="handleParadigmChange"
-            class="writer-select"
-          >
-            <option value="" disabled>请选择范式...</option>
-            <option 
-              v-for="p in paradigmList" 
-              :key="p.id" 
-              :value="p.id"
-            >
-              {{ p.icon }} {{ p.name }}
-            </option>
-          </select>
+          <div class="custom-select" @click="toggleDropdown">
+            <div class="custom-select-trigger">
+              <template v-if="activeParadigm">
+                <IconLibrary :name="activeParadigm.icon" :size="16" />
+                <span>{{ activeParadigm.name }}</span>
+              </template>
+              <span v-else class="text-muted">请选择范式...</span>
+              <IconLibrary name="expand" :size="14" class="ml-auto" />
+            </div>
+            <div v-show="isDropdownOpen" class="custom-select-dropdown">
+              <div
+                v-for="p in paradigmList"
+                :key="p.id"
+                @click.stop="selectParadigm(p)"
+                :class="['custom-select-option', { 'selected': selectedParadigmId === p.id }]"
+              >
+                <IconLibrary :name="p.icon" :size="16" />
+                <span>{{ p.name }}</span>
+              </div>
+            </div>
+          </div>
           <p v-if="activeParadigm" class="text-xs text-muted mt-2">
             {{ activeParadigm.description }}
           </p>
@@ -174,7 +181,7 @@
 </template>
 
 <script setup>
-import { ref, computed, onMounted } from 'vue'
+import { ref, computed, onMounted, onUnmounted } from 'vue'
 import { storeToRefs } from 'pinia'
 import { useAppStore } from '../stores/app'
 import IconLibrary from './icons/IconLibrary.vue'
@@ -189,6 +196,33 @@ const { paradigmWriterState, activeParadigm, generatedContent } = storeToRefs(ap
 const selectedParadigmId = ref('')
 const currentSectionIndex = ref(0)
 const paradigmList = ref([])
+const isDropdownOpen = ref(false)
+
+// 下拉框控制
+const toggleDropdown = () => {
+  isDropdownOpen.value = !isDropdownOpen.value
+}
+
+const selectParadigm = (p) => {
+  selectedParadigmId.value = p.id
+  isDropdownOpen.value = false
+  handleParadigmChange()
+}
+
+// 点击外部关闭下拉框
+const closeDropdown = (e) => {
+  if (!e.target.closest('.custom-select')) {
+    isDropdownOpen.value = false
+  }
+}
+
+onMounted(() => {
+  document.addEventListener('click', closeDropdown)
+})
+
+onUnmounted(() => {
+  document.removeEventListener('click', closeDropdown)
+})
 
 // 加载完整的范式列表（包含自定义范式）
 const loadAllParadigms = () => {
@@ -649,4 +683,59 @@ onMounted(() => {
   opacity: 0.5;
   cursor: not-allowed;
 }
+
+/* 自定义下拉框 */
+.custom-select {
+  position: relative;
+  width: 100%;
+}
+
+.custom-select-trigger {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+  padding: var(--space-3);
+  background: var(--bg-primary);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-lg);
+  cursor: pointer;
+  transition: all var(--transition-fast);
+}
+
+.custom-select-trigger:hover {
+  border-color: var(--accent-primary);
+}
+
+.custom-select-dropdown {
+  position: absolute;
+  top: 100%;
+  left: 0;
+  right: 0;
+  margin-top: var(--space-1);
+  background: var(--bg-elevated);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-lg);
+  box-shadow: var(--shadow-lg);
+  z-index: 100;
+  max-height: 240px;
+  overflow-y: auto;
+}
+
+.custom-select-option {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+  padding: var(--space-3);
+  cursor: pointer;
+  transition: all var(--transition-fast);
+}
+
+.custom-select-option:hover {
+  background: var(--bg-sunken);
+}
+
+.custom-select-option.selected {
+  background: var(--info-bg);
+  color: var(--accent-primary);
+}
 </style>