fix(im): 迁移 Element UI 图标并修复 Vue 3 兼容问题

- 新增 migrate-legacy-icons 脚本，批量将旧图标替换为 legacy-el-icon 组件
- 多个组件中将 <i class="el-icon-*"> 统一改为 <legacy-el-icon name="el-icon-*">
- 将 size="mini"/"medium" 调整为 Element Plus 的 small/default
- 新增 legacy-el-icon 全局组件及图标映射逻辑

im/src/components/chat/messaege/AudioMessage.vue

@@ -2,9 +2,9 @@
   <div class="audio-message">
     <div class="videodisc">
       <div class="disc" :class="{ play: isPlay }" @click="toPlay">
-        <i v-if="loading" class="el-icon-loading" />
-        <i v-else-if="isPlay" class="el-icon-video-pause" />
-        <i v-else class="el-icon-video-play" />
+        <legacy-el-icon v-if="loading" name="el-icon-loading" />
+        <legacy-el-icon v-else-if="isPlay" name="el-icon-video-pause" />
+        <legacy-el-icon v-else name="el-icon-video-play" />
         <audio
           ref="audio"
           type="audio/mp3"
@@ -17,7 +17,7 @@
     </div>
     <div class="detail">
       <div class="text">
-        <i class="el-icon-service" />
+        <legacy-el-icon name="el-icon-service" />
         <span>{{ getCurrDuration }} / {{ getTotalDuration }}</span>
       </div>
       <div class="process">

im/src/components/chat/messaege/CodeMessage.vue

@@ -7,10 +7,14 @@
       'full-screen': fullscreen,
     }"
   >
+    <legacy-el-icon
+      v-if="fullscreen"
+      name="el-icon-close"
+      @click="fullscreen = !fullscreen"
+    />
     <i
-      :class="
-        fullscreen ? 'el-icon-close' : 'iconfont icon-tubiao_chakangongyi'
-      "
+      v-else
+      class="iconfont icon-tubiao_chakangongyi"
       @click="fullscreen = !fullscreen"
     />
     <pre class="lum-scrollbar" v-html="formatCode(code, lang)" />

im/src/components/chat/messaege/VisitCardMessage.vue

@@ -9,7 +9,7 @@
       </div>
       <div class="tools flex-center">
         <span class="flex-center pointer">
-          <i class="el-icon-plus" /> 加好友
+          <legacy-el-icon name="el-icon-plus" /> 加好友
         </span>
       </div>
     </div>

im/src/components/chat/messaege/VoteMessage.vue

@@ -5,16 +5,13 @@
         <div class="vheader">
           <p>
             {{ answer_mode == 1 ? "[多选投票]" : "[单选投票]" }}
-            <i
+            <legacy-el-icon
               v-show="is_vote"
               class="pointer"
-              :class="{
-                'el-icon-loading': refresh,
-                'el-icon-refresh': !refresh,
-              }"
+              :name="refresh ? 'el-icon-loading' : 'el-icon-refresh'"
               title="刷新投票结果"
               @click="loadRefresh"
-            ></i>
+            />
           </p>
           <p>{{ title }}</p>
         </div>