feat: 重构聊天时间线与附件上传交互

- 管理端和用户中心统一切换到 chatTime 时间线模型，按真实 assistant/tool 时序渲染

- 收紧工具气泡与 JSON 展示样式，保留同气泡内的工具状态更新

- 回形针直接触发文件选择，附件列表上移到输入框上方并补充共享 helper 测试

easyflow-ui-usercenter/app/src/views/chatHistory/index.vue

@@ -1,7 +1,10 @@
 <script setup lang="ts">
+import type { ChatTimeTimelineItem } from '@easyflow/types';
+
 import { computed, onMounted, ref, watch } from 'vue';
 import { useRoute, useRouter } from 'vue-router';
 
+import { ChatTimeHistoryMapper } from '@easyflow/utils';
 import { Delete, Edit, Search } from '@element-plus/icons-vue';
 import {
   ElButton,
@@ -43,7 +46,8 @@ const pageState = ref({
 const drawerVisible = ref(false);
 const drawerLoading = ref(false);
 const currentSession = ref<any>();
-const messageList = ref<any[]>([]);
+const messageList = ref<ChatTimeTimelineItem[]>([]);
+const loadedMessageRecordCount = ref(0);
 const messagePage = ref({
   total: 0,
   pageNumber: 1,
@@ -123,6 +127,7 @@ async function openSession(sessionId: string | number) {
   }
   currentSession.value = summaryRes.data;
   messageList.value = [];
+  loadedMessageRecordCount.value = 0;
   messagePage.value = {
     total: 0,
     pageNumber: 1,
@@ -162,32 +167,22 @@ async function loadMessages(reset = false) {
   } else {
     messageList.value = [...normalized, ...messageList.value];
   }
+  loadedMessageRecordCount.value = reset
+    ? (res.data?.records || []).length
+    : loadedMessageRecordCount.value + (res.data?.records || []).length;
   messagePage.value.total = res.data?.total || 0;
   messagePage.value.pageNumber = nextPageNumber;
 }
 
 function normalizeMessages(records: any[]) {
-  return [...records]
-    .reverse()
-    .map((item: any) => ({
-      key: String(item.id),
-      role: item.senderRole === 'assistant' ? 'assistant' : 'user',
-      content:
-        item.senderRole === 'assistant'
-          ? String(item.contentText || '').replace(/^Final Answer:\s*/i, '')
-          : item.contentText,
-      placement: item.senderRole === 'assistant' ? 'start' : 'end',
-      created: item.created,
-      chains: Array.isArray(item.contentPayload?.chains)
-        ? item.contentPayload.chains
-        : undefined,
-    }));
+  return ChatTimeHistoryMapper.fromHistoryRecords([...records].reverse());
 }
 
 function closeDrawer() {
   drawerVisible.value = false;
   currentSession.value = undefined;
   messageList.value = [];
+  loadedMessageRecordCount.value = 0;
   router.replace({ path: '/chatHistory', query: {} });
 }
 
@@ -349,7 +344,7 @@ function formatTime(value?: string) {
       <div class="flex-1 overflow-hidden">
         <div class="mb-4 flex justify-center">
           <ElButton
-            v-if="messageList.length < messagePage.total"
+            v-if="loadedMessageRecordCount < messagePage.total"
             text
             type="primary"
             @click="loadMessages(false)"