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-admin/app/src/views/ai/chatHistory/index.vue

@@ -1,7 +1,10 @@
 <script setup lang="ts">
+import type { ChatTimeTimelineItem } from '@easyflow/types';
+
 import { computed, onMounted, ref } from 'vue';
 
 import { useEasyFlowDrawer } from '@easyflow/common-ui';
+import { ChatTimeHistoryMapper } from '@easyflow/utils';
 
 import { Search } from '@element-plus/icons-vue';
 import {
@@ -43,7 +46,8 @@ const quickRangeOptions = [
 
 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,
@@ -63,7 +67,7 @@ const [Drawer, drawerApi] = useEasyFlowDrawer({
 });
 
 const hasMoreMessages = computed(
-  () => messageList.value.length < messagePage.value.total,
+  () => loadedMessageRecordCount.value < messagePage.value.total,
 );
 
 const selectedSessionId = computed(() =>
@@ -111,6 +115,7 @@ async function openSession(sessionId: number | string) {
     sessions.value.find((item: any) => String(item.id) === String(sessionId)) ||
     undefined;
   messageList.value = [];
+  loadedMessageRecordCount.value = 0;
   messagePage.value = {
     total: 0,
     pageNumber: 1,
@@ -154,31 +159,15 @@ async function loadMessages(reset = false) {
   messageList.value = reset
     ? normalized
     : [...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,
-    created: item.created,
-    senderName: item.senderName,
-    chains: Array.isArray(item.contentPayload?.chains)
-      ? item.contentPayload.chains.map((chain: any) =>
-          chain?.id
-            ? chain
-            : {
-                ...chain,
-                thinkingExpanded: false,
-              },
-        )
-      : [],
-  }));
+  return ChatTimeHistoryMapper.fromHistoryRecords([...records].reverse());
 }
 
 function changePage(pageNumber: number) {