update: HistoryButton icon from Document to Clock for improved clarity

src/components/chat/HistoryButton.vue

@@ -2,7 +2,7 @@
   <el-dropdown trigger="hover" @command="handleHistorySelect">
     <el-button 
       :class="['history-btn', { 'icon-only': iconOnly }]" 
-      :icon="Document" 
+      :icon="Clock" 
       text 
       bg
     >
@@ -37,7 +37,7 @@
 <script setup>
 import { computed } from 'vue'
 import { useChatStore } from '@/store/chat'
-import { Document, Delete } from '@element-plus/icons-vue'
+import { Clock, Delete } from '@element-plus/icons-vue'
 import { ElMessageBox } from 'element-plus'
 
 const props = defineProps({