refactor: split project into web and server directories

- Move frontend to web/ directory
- Add server/ directory for backend
- Restructure project for前后端分离架构

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/src/composables/useChat.js

@@ -0,0 +1,102 @@
+import { nextTick, ref } from 'vue'
+
+const initialMessages = [
+  {
+    id: 1,
+    role: 'agent',
+    text: '我已读取当前报销、发票、行程和制度命中情况。当前建议：优先处理即将超时与高风险单据。'
+  },
+  {
+    id: 2,
+    role: 'user',
+    text: '请列出今天最需要关注的风险。'
+  },
+  {
+    id: 3,
+    role: 'agent',
+    text: '主要风险包括：3 笔单据将在 30 分钟内超时，市场部存在 2 笔高风险差旅报销，另有 1 笔报销缺少酒店入住清单。'
+  }
+]
+
+export const prompts = ['生成审批意见', '列出补件清单', '解释风险原因', '生成运营简报']
+
+export function useChat(activeView) {
+  const messages = ref([...initialMessages])
+  const draft = ref('')
+  const uploadedFiles = ref([])
+  const messageList = ref(null)
+  const activeCase = ref(null)
+
+  function agentReply(text) {
+    const c = activeCase.value
+    if (text.includes('超时') || text.includes('SLA')) {
+      return '当前最紧急的是 3 笔即将超时单据，建议先按剩余处理时长排序，并把缺附件单据转给申请人补齐。'
+    }
+    if (text.includes('高风险') || text.includes('风险')) {
+      return '高风险主要集中在市场部差旅报销，风险点包括住宿超标、重复发票疑似命中、行程说明缺失。建议人工复核后再通过。'
+    }
+    if (text.includes('部门')) {
+      return '从待处理金额看，销售部与研发中心占比最高；从异常占比看，市场部更需要优先关注。'
+    }
+    if (text.includes('简报')) {
+      return '运营简报：今日待审批 12 单，高风险 4 单，平均审批 5.6h，SLA 达成率 96%。建议优先处理差旅报销和即将超时单据。'
+    }
+    if (text.includes('补件') || text.includes('附件')) {
+      return '建议补件清单：酒店入住水单、完整行程单、发票原件或验真结果、直属经理确认记录。'
+    }
+    if (text.includes('审批意见')) {
+      return c
+        ? `${c.id} 建议审批意见：费用归属与预算中心基本匹配，请补充必要说明后通过。`
+        : '建议审批意见：当前单据存在待确认项，请先完成风险核查和附件补齐后再审批。'
+    }
+    return '收到。我可以继续帮你拆解异常原因、比较部门趋势、生成审批意见，或整理一份今日报销运营简报。'
+  }
+
+  function scrollToBottom() {
+    nextTick(() => messageList.value?.scrollTo({ top: messageList.value.scrollHeight, behavior: 'smooth' }))
+  }
+
+  function sendMessage() {
+    const text = draft.value.trim()
+    if (!text) return false
+    messages.value.push({ id: Date.now(), role: 'user', text })
+    draft.value = ''
+    setTimeout(() => {
+      messages.value.push({ id: Date.now() + 1, role: 'agent', text: agentReply(text) })
+      scrollToBottom()
+    }, 260)
+    return true
+  }
+
+  function handleUpload(event) {
+    uploadedFiles.value = Array.from(event.target.files ?? []).map((file) => ({
+      name: file.name,
+      size: file.size
+    }))
+    if (uploadedFiles.value.length) {
+      const names = uploadedFiles.value.map((file) => file.name).join('、')
+      messages.value.push({
+        id: Date.now(),
+        role: 'agent',
+        text: `已接收 ${uploadedFiles.value.length} 个附件：${names}。我会优先核对发票验真、费用标准、预算归属和必要审批材料。`
+      })
+      scrollToBottom()
+    }
+  }
+
+  function openChat(request) {
+    activeCase.value = request
+    activeView.value = 'chat'
+    nextTick(() => messageList.value?.scrollTo({ top: messageList.value.scrollHeight }))
+  }
+
+  function openNewChat() {
+    activeCase.value = null
+    activeView.value = 'chat'
+  }
+
+  return {
+    messages, draft, uploadedFiles, messageList, activeCase, prompts,
+    sendMessage, handleUpload, openChat, openNewChat, scrollToBottom
+  }
+}