bi-agent-optimize.patch

diff --git a/app/llm.py b/app/llm.py
index b0f3092..d434989 100644
--- a/app/llm.py
+++ b/app/llm.py
@@ -1,14 +1,33 @@
 """LLM 客户端：用 OpenAI 兼容协议，同时支持通义千问 Qwen 与 DeepSeek。
 切换模型只需改 .env，不改代码。"""
+import os
+
 from openai import OpenAI
 from .config import LLM_BASE_URL, LLM_MODEL, LLM_API_KEY
 
-_client = OpenAI(base_url=LLM_BASE_URL, api_key=LLM_API_KEY)
+# 稳定性关键：上游 LLM 偶发挂起时，无超时 = 整个 /api/ask 永久转圈、连接被一直占着。
+# timeout 让请求最多等 LLM_TIMEOUT 秒；max_retries 处理偶发网络抖动（指数退避）。
+LLM_TIMEOUT = float(os.getenv("LLM_TIMEOUT", "60"))
+LLM_MAX_RETRIES = int(os.getenv("LLM_MAX_RETRIES", "2"))
+
+# 惰性构造：OpenAI() 在 key 为空时构造即抛异常 → 原来没配 .env 连 import 都崩、/health 都起不来。
+# 改为首次调用时才建客户端：服务能正常启动，只有真正用到 LLM 时才报清晰错误。
+_client = None
+
+
+def _get_client() -> OpenAI:
+    global _client
+    if _client is None:
+        if not LLM_API_KEY:
+            raise RuntimeError("LLM_API_KEY 未配置：请在 .env 中设置（参考 README 环境变量一节）")
+        _client = OpenAI(base_url=LLM_BASE_URL, api_key=LLM_API_KEY,
+                         timeout=LLM_TIMEOUT, max_retries=LLM_MAX_RETRIES)
+    return _client
 
 
 def chat(messages, temperature: float = 0.0, **kw) -> str:
     """同步对话，返回文本。Text2SQL 等确定性任务用 temperature=0。"""
-    resp = _client.chat.completions.create(
+    resp = _get_client().chat.completions.create(
         model=LLM_MODEL, messages=messages, temperature=temperature, **kw
     )
     return resp.choices[0].message.content or ""
@@ -16,7 +35,7 @@ def chat(messages, temperature: float = 0.0, **kw) -> str:
 
 def chat_stream(messages, temperature: float = 0.3, **kw):
     """流式对话，逐 token 产出（供洞察生成的 SSE 输出）。"""
-    stream = _client.chat.completions.create(
+    stream = _get_client().chat.completions.create(
         model=LLM_MODEL, messages=messages, temperature=temperature, stream=True, **kw
     )
     for chunk in stream:
diff --git a/app/main.py b/app/main.py
index 8bd2e7c..feb73fa 100644
--- a/app/main.py
+++ b/app/main.py
@@ -12,6 +12,7 @@
 """
 import asyncio
 import json
+import logging
 
 from fastapi import FastAPI, Depends, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
@@ -25,7 +26,10 @@ from .auth import router as auth_router, get_current_user
 from .database import get_db, init_db
 from .models import User, Conversation, Message
 
-from .config import CORS_ALLOW_ORIGINS
+from .config import CORS_ALLOW_ORIGINS, JWT_SECRET
+
+logger = logging.getLogger("cheshijing")
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s %(message)s")
 
 app = FastAPI(title="车市镜 · 新能源车市情报 Agent")
 # CORS：dev 默认放行全部；生产用 CORS_ALLOW_ORIGINS 收紧到正式域名（§17/§18）。
@@ -45,6 +49,9 @@ except Exception as _e:  # noqa: BLE001
 @app.on_event("startup")
 def _startup():
     init_db()  # 幂等建应用层表（users/conversation/message/kb_document）
+    # 安全自检：JWT 弱密钥在生产环境是致命的（任何人可伪造任意用户 token）。
+    if JWT_SECRET == "dev-insecure-change-me":
+        logger.warning("JWT_SECRET 仍是默认弱密钥！上线/演示前务必在 .env 设置随机强密钥（如 openssl rand -hex 32）")
 
 
 class Ask(BaseModel):
@@ -119,16 +126,20 @@ def _insight_pieces(text: str, n: int = 24):
 
 @app.post("/api/ask")
 async def ask(body: Ask, user: User = Depends(get_current_user), db: Session = Depends(get_db)):
-    """SSE（§9.1）：intent → [sql] → [rows] → [chart] → insight(逐段 delta) → [citation...] → done。
+    """SSE（§9.1）：stage(accepted) → intent → [sql] → [rows] → [chart] → insight(逐段 delta) → [citation...] → done。
     纯 RAG 无 sql/rows/chart，只有 insight(答案)+citation；出错推 error。"""
     async def gen():
+        # 体验关键：agent 整体跑完才有第一个业务事件，期间用户毫无反馈。
+        # 先推一个 stage 事件，前端立刻把「已接收，分析中」亮起来（旧前端不识别会安全忽略）。
+        yield {"event": "stage", "data": json.dumps(
+            {"stage": "accepted", "message": "已接收，正在分析问题…"}, ensure_ascii=False)}
         try:
             # 图是同步阻塞，丢线程池跑，避免堵事件循环
             state = await asyncio.to_thread(run_agent, body.question, user.id, [])
         except Exception as e:  # noqa: BLE001
             yield {"event": "error", "data": json.dumps(
                 {"code": "AGENT_ERROR", "message": "处理失败，请换种问法或缩小范围。"}, ensure_ascii=False)}
-            print(f"[ask] run_agent 失败: {e}")
+            logger.exception(f"[ask] run_agent 失败 user={user.id} q={body.question[:80]!r}: {e}")
             return
 
         conv_id, msg_id = _persist(db, user, body.question, state, body.conversation_id)
@@ -157,7 +168,7 @@ async def ask(body: Ask, user: User = Depends(get_current_user), db: Session = D
             {"msg_id": msg_id, "conversation_id": conv_id, "has_answer": state.get("has_answer", True)},
             ensure_ascii=False)}
 
-    return EventSourceResponse(gen())
+    return EventSourceResponse(gen(), ping=15)
 
 
 # ---------------------------------------------------------------- 历史会话
diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index b7166b9..621132e 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -1,5 +1,5 @@
 <script setup>
-import { ref } from 'vue'
+import { ref, computed, onMounted, onBeforeUnmount } from 'vue'
 import Sidebar from './components/Sidebar.vue'
 import TopBar from './components/TopBar.vue'
 import EmptyState from './components/EmptyState.vue'
@@ -13,11 +13,39 @@ import { useAuth } from './composables/useAuth.js'
 const { isAuthed, state: auth, logout } = useAuth()
 const { conversations, activeId, messages, sending, newConversation, selectConversation, deleteConversation, send, stop } = useChat()
 const showKb = ref(false)
+const showSide = ref(false)   // 移动端侧栏抽屉
 
 function onAsk(q) {
   if (!activeId.value) newConversation()
   send(q)
 }
+function onSelect(id) {
+  selectConversation(id)
+  showSide.value = false      // 移动端选完会话自动收起抽屉
+}
+function onNew() {
+  newConversation()
+  showSide.value = false
+}
+
+// 最后一条用户提问 → Composer 按 ↑ 回填（类终端 history）
+const lastQuestion = computed(() => {
+  const list = messages.value
+  for (let i = list.length - 1; i >= 0; i--) {
+    if (list[i].role === 'user') return list[i].content
+  }
+  return ''
+})
+
+// 全局快捷键：Cmd/Ctrl + K 新建对话（重度用户肌肉记忆）
+function onHotkey(e) {
+  if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === 'k') {
+    e.preventDefault()
+    if (isAuthed.value && !sending.value) newConversation()
+  }
+}
+onMounted(() => window.addEventListener('keydown', onHotkey))
+onBeforeUnmount(() => window.removeEventListener('keydown', onHotkey))
 </script>
 
 <template>
@@ -26,15 +54,20 @@ function onAsk(q) {
 
   <div v-else class="app">
     <Sidebar
+      :class="{ 'side-open': showSide }"
       :conversations="conversations" :activeId="activeId" :user="auth.user"
-      @new="newConversation" @select="selectConversation" @delete="deleteConversation" @open-kb="showKb = true" />
+      @new="onNew" @select="onSelect" @delete="deleteConversation" @open-kb="showKb = true" />
+    <div v-if="showSide" class="side-mask" @click="showSide = false"></div>
 
     <main class="main">
+      <button class="burger" aria-label="打开会话列表" @click="showSide = true">
+        <span></span><span></span><span></span>
+      </button>
       <TopBar :user="auth.user" @logout="logout" />
       <div class="stage">
         <EmptyState v-if="!messages.length" @ask="onAsk" />
         <MessageList v-else :messages="messages" @ask="onAsk" />
-        <Composer :sending="sending" @send="onAsk" @stop="stop" />
+        <Composer :sending="sending" :lastQuestion="lastQuestion" @send="onAsk" @stop="stop" />
       </div>
     </main>
 
@@ -44,10 +77,31 @@ function onAsk(q) {
 
 <style scoped>
 .app { display: flex; height: 100%; }
-.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }
+.main { flex: 1; display: flex; flex-direction: column; min-width: 0; position: relative; }
 .stage { flex: 1; display: flex; flex-direction: column; min-height: 0; }
 
+.burger { display: none; }
+.side-mask { display: none; }
+
+/* 移动端：侧栏改为抽屉（之前是直接 display:none，历史会话/知识库完全不可达） */
 @media (max-width: 760px) {
-  .app :deep(.sidebar) { display: none; }
+  .app :deep(.sidebar) {
+    position: fixed; left: 0; top: 0; bottom: 0; z-index: 60;
+    transform: translateX(-100%); transition: transform .22s ease;
+    box-shadow: 8px 0 30px rgba(0,0,0,.35);
+  }
+  .app :deep(.sidebar.side-open) { transform: translateX(0); }
+  .side-mask {
+    display: block; position: fixed; inset: 0; z-index: 50;
+    background: rgba(8,12,20,.5); animation: fadeIn .18s ease;
+  }
+  .burger {
+    display: flex; flex-direction: column; justify-content: center; gap: 4px;
+    position: absolute; left: 14px; top: 14px; z-index: 30;
+    width: 32px; height: 30px; padding: 0 7px; border-radius: var(--r-sm);
+    background: var(--panel); border: 1px solid var(--line);
+  }
+  .burger span { height: 1.6px; background: var(--tx-700); border-radius: 2px; }
+  .main :deep(.topbar) { padding-left: 58px; }
 }
 </style>
diff --git a/frontend/src/api/events.js b/frontend/src/api/events.js
index 23f5532..2bddc78 100644
--- a/frontend/src/api/events.js
+++ b/frontend/src/api/events.js
@@ -33,6 +33,10 @@ export function normalizeEvent(event, raw) {
   const o = (d && typeof d === 'object') ? d : {}
 
   switch (name) {
+    case 'stage':
+      // 后端在 agent 起跑前立即推送（即时反馈）；旧后端没有此事件，不影响兼容
+      return { type: 'stage', stage: o.stage || '', message: o.message || '' }
+
     case 'intent':
       return { type: 'intent', intent: o.intent || 'sql', confidence: o.confidence ?? null, conversationId: o.conversation_id ?? null }
 
diff --git a/frontend/src/components/AssistantMessage.vue b/frontend/src/components/AssistantMessage.vue
index 8c30e3a..f8f295d 100644
--- a/frontend/src/components/AssistantMessage.vue
+++ b/frontend/src/components/AssistantMessage.vue
@@ -25,6 +25,7 @@ const FALLBACK_QS = ['2025年纯电销量Top10', '理想和小米SU7谁卖得多
         <div class="err-title">没太理解这个问题</div>
         <p class="err-sub">{{ msg.error?.message || '换一种问法试试，或点下面的示例问题：' }}</p>
         <div class="chips">
+          <button v-if="msg.question" class="retry" @click="emit('ask', msg.question)">↻ 重试该问题</button>
           <button v-for="q in FALLBACK_QS" :key="q" @click="emit('ask', q)">{{ q }}</button>
         </div>
       </div>
@@ -66,4 +67,6 @@ const FALLBACK_QS = ['2025年纯电销量Top10', '理想和小米SU7谁卖得多
 .chips { display: flex; flex-wrap: wrap; gap: 8px; }
 .chips button { font-size: 12.5px; color: var(--ink-800); background: var(--sql-soft); border: 1px solid var(--line); border-radius: var(--r-pill); padding: 7px 15px; transition: background .12s, border-color .12s; }
 .chips button:hover { background: var(--jade-50); border-color: var(--jade-300); }
+.chips .retry { background: var(--jade-600); color: #fff; border-color: var(--jade-600); font-weight: 700; }
+.chips .retry:hover { background: var(--jade-700); border-color: var(--jade-700); }
 </style>
diff --git a/frontend/src/components/ChartCard.vue b/frontend/src/components/ChartCard.vue
index 827b887..66f30dc 100644
--- a/frontend/src/components/ChartCard.vue
+++ b/frontend/src/components/ChartCard.vue
@@ -35,6 +35,12 @@ onBeforeUnmount(() => {
   chart.value?.dispose()
 })
 watch(() => props.option, render, { deep: true })
+
+// 供父组件「下载图表 PNG」：导出当前画布（2x 像素密度，白底）
+function getDataURL() {
+  return chart.value?.getDataURL({ type: 'png', pixelRatio: 2, backgroundColor: '#fff' }) || null
+}
+defineExpose({ getDataURL })
 </script>
 
 <template>
diff --git a/frontend/src/components/Composer.vue b/frontend/src/components/Composer.vue
index 8d4adeb..e3f0724 100644
--- a/frontend/src/components/Composer.vue
+++ b/frontend/src/components/Composer.vue
@@ -2,7 +2,10 @@
 // 输入区：自适应高度文本框 + 发送/停止。Enter 发送，Shift+Enter 换行。
 import { ref, nextTick, watch } from 'vue'
 
-const props = defineProps({ sending: { type: Boolean, default: false } })
+const props = defineProps({
+  sending: { type: Boolean, default: false },
+  lastQuestion: { type: String, default: '' },   // 重度用户：空输入框按 ↑ 调回上一条提问改着发
+})
 const emit = defineEmits(['send', 'stop'])
 
 const text = ref('')
@@ -27,6 +30,17 @@ function onKey(e) {
   if (e.key === 'Enter' && !e.shiftKey && !e.isComposing) {
     e.preventDefault()
     submit()
+    return
+  }
+  // 空输入框按 ↑：回填上一条提问（类终端 history），光标移到末尾方便就地修改
+  if (e.key === 'ArrowUp' && !text.value && props.lastQuestion) {
+    e.preventDefault()
+    text.value = props.lastQuestion
+    nextTick(() => {
+      resize()
+      const el = ta.value
+      if (el) el.setSelectionRange(el.value.length, el.value.length)
+    })
   }
 }
 </script>
diff --git a/frontend/src/components/DataResultCard.vue b/frontend/src/components/DataResultCard.vue
index d28d58b..915441e 100644
--- a/frontend/src/components/DataResultCard.vue
+++ b/frontend/src/components/DataResultCard.vue
@@ -4,12 +4,31 @@
 import { ref, computed, watch } from 'vue'
 import ChartCard from './ChartCard.vue'
 import { normalizeChartSpec, buildOptionByType, TYPE_LABEL } from '@/utils/chart.js'
+import { toCSV, downloadFile, downloadDataURL, copyText, exportName } from '@/utils/export.js'
 
 const props = defineProps({
   msg: { type: Object, required: true },
   streaming: { type: Boolean, default: false },
 })
 
+const chartRef = ref(null)
+const copied = ref(false)
+
+// —— 重度用户三件套：导出 CSV / 下载图表 PNG / 复制结论 —— //
+function exportCSV() {
+  downloadFile(exportName('车市镜数据', 'csv'), toCSV(props.msg.columns, props.msg.rows), 'text/csv;charset=utf-8')
+}
+function exportPNG() {
+  const url = chartRef.value?.getDataURL()
+  if (url) downloadDataURL(exportName('车市镜图表', 'png'), url)
+}
+async function copyInsight() {
+  if (await copyText(props.msg.insight || '')) {
+    copied.value = true
+    setTimeout(() => { copied.value = false }, 1500)
+  }
+}
+
 const hasData = computed(() => props.msg.rows?.length > 0 && props.msg.columns?.length > 0)
 // 后端图表描述符 → 维度/度量/默认图型/可切图型集合
 const spec = computed(() => hasData.value
@@ -38,12 +57,27 @@ const option = computed(() =>
           <button v-for="t in types" :key="t.key"
             :class="{ on: type === t.key }" @click="type = t.key">{{ t.label }}</button>
         </div>
+        <div class="tools">
+          <button class="tool" title="下载图表 PNG" @click="exportPNG">
+            <svg viewBox="0 0 20 20" width="14" height="14"><path d="M10 3v9m0 0l-3.5-3.5M10 12l3.5-3.5M4 16h12" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round"/></svg>
+            图
+          </button>
+          <button class="tool" title="导出数据 CSV" @click="exportCSV">
+            <svg viewBox="0 0 20 20" width="14" height="14"><path d="M4 4h12v12H4z M4 8.5h12 M8.5 4v12" fill="none" stroke="currentColor" stroke-width="1.4"/></svg>
+            CSV
+          </button>
+        </div>
       </div>
-      <ChartCard :option="option" />
+      <ChartCard ref="chartRef" :option="option" />
     </div>
 
     <div v-if="msg.insight || streaming" class="insight">
-      <div class="insight-head">结论与归因</div>
+      <div class="insight-head">
+        结论与归因
+        <button class="copy" :class="{ ok: copied }" :title="copied ? '已复制' : '复制结论'" @click="copyInsight">
+          {{ copied ? '✓ 已复制' : '复制' }}
+        </button>
+      </div>
       <div class="insight-body">
         <span class="text">{{ msg.insight }}</span><span v-if="streaming" class="cursor"></span>
       </div>
@@ -66,6 +100,25 @@ const option = computed(() =>
 
 /* 分段图型切换 */
 .switch { margin-left: auto; display: inline-flex; background: var(--panel-2); border: 1px solid var(--line); border-radius: var(--r-pill); padding: 3px; }
+
+/* 导出工具：图 PNG / 数据 CSV。无切换器时自己靠右，有则贴在切换器右侧 */
+.tools { display: inline-flex; gap: 6px; margin-left: auto; }
+.switch ~ .tools { margin-left: 0; }
+.tool {
+  display: inline-flex; align-items: center; gap: 5px;
+  font-size: 11.5px; font-weight: 600; color: var(--tx-500);
+  border: 1px solid var(--line); border-radius: var(--r-pill); padding: 4px 10px;
+  background: var(--panel-2); transition: color .12s, border-color .12s;
+}
+.tool:hover { color: var(--sql-accent); border-color: var(--sql-accent); }
+
+.insight-head .copy {
+  float: right; font-family: var(--f-sans); font-size: 11px; font-weight: 600;
+  color: var(--tx-500); border: 1px solid var(--line); border-radius: var(--r-pill);
+  padding: 2px 10px; letter-spacing: 0; text-transform: none; transition: color .12s, border-color .12s;
+}
+.insight-head .copy:hover { color: var(--sql-accent); border-color: var(--sql-accent); }
+.insight-head .copy.ok { color: var(--jade-600); border-color: var(--jade-300); }
 .switch button {
   font-size: 12px; font-weight: 600; color: var(--tx-500); padding: 5px 12px; border-radius: var(--r-pill);
   transition: color .15s, background .15s; white-space: nowrap;
diff --git a/frontend/src/components/KnowledgeAnswer.vue b/frontend/src/components/KnowledgeAnswer.vue
index 2224ac2..5633ea1 100644
--- a/frontend/src/components/KnowledgeAnswer.vue
+++ b/frontend/src/components/KnowledgeAnswer.vue
@@ -2,10 +2,23 @@
 // 知识问答脑：答案正文 + 来源引用卡（文档名 / 章节 heading_path / 页码，可点击溯源）。
 // 引用结构对齐后端 §5.5：{doc_id, page_no, chunk_id, heading_path, title}。
 import { ref } from 'vue'
+import { copyText } from '@/utils/export.js'
 const props = defineProps({
   msg: { type: Object, required: true },
   streaming: { type: Boolean, default: false },
 })
+const copied = ref(false)
+async function copyAnswer() {
+  // 连同引用一起复制 —— 重度用户常把答案贴进周报/IM，带出处更可信
+  const cites = (props.msg.citations || [])
+    .map((c, i) => `[${i + 1}] 《${c.title || '文档 #' + c.doc_id}》 ${c.heading_path || ''} P${c.page_no}`)
+    .join('\n')
+  const text = (props.msg.insight || '') + (cites ? `\n\n来源：\n${cites}` : '')
+  if (await copyText(text)) {
+    copied.value = true
+    setTimeout(() => { copied.value = false }, 1500)
+  }
+}
 // 当前展开溯源详情的引用索引（后端暂无文档查看器，点开就地展示出处定位信息）
 const openIdx = ref(-1)
 function toggle(i) { openIdx.value = openIdx.value === i ? -1 : i }
@@ -19,6 +32,9 @@ function pathParts(c) {
   <div class="answer">
     <div class="ans-body">
       <span class="text">{{ msg.insight }}</span><span v-if="streaming" class="cursor"></span>
+      <button v-if="msg.insight && !streaming" class="copy" :class="{ ok: copied }" @click="copyAnswer">
+        {{ copied ? '✓ 已复制（含来源）' : '复制答案' }}
+      </button>
     </div>
 
     <div v-if="msg.citations && msg.citations.length" class="citations">
@@ -50,6 +66,13 @@ function pathParts(c) {
 <style scoped>
 .answer { display: flex; flex-direction: column; gap: 18px; }
 .ans-body { font-size: 15px; line-height: 1.85; color: var(--tx-900); white-space: pre-wrap; }
+.ans-body .copy {
+  display: block; margin-top: 10px; font-size: 11.5px; font-weight: 600; color: var(--tx-500);
+  border: 1px solid var(--line); border-radius: var(--r-pill); padding: 3px 12px;
+  transition: color .12s, border-color .12s;
+}
+.ans-body .copy:hover { color: var(--rag-accent); border-color: var(--rag-accent); }
+.ans-body .copy.ok { color: var(--jade-600); border-color: var(--jade-300); }
 .cursor { display: inline-block; width: 7px; height: 15px; background: var(--rag-accent); margin-left: 2px; vertical-align: -2px; animation: blink 1s step-start infinite; }
 
 .citations { border-top: 1px dashed var(--line-strong); padding-top: 14px; }
diff --git a/frontend/src/components/Sidebar.vue b/frontend/src/components/Sidebar.vue
index b38eb2d..390ad1f 100644
--- a/frontend/src/components/Sidebar.vue
+++ b/frontend/src/components/Sidebar.vue
@@ -1,13 +1,21 @@
 <script setup>
-// 左侧栏：品牌 + 新建对话 + 会话历史 + 知识库入口 + 用户位（上线预留）。
+// 左侧栏：品牌 + 新建对话 + 会话搜索 + 会话历史 + 知识库入口 + 用户位（上线预留）。
+import { ref, computed } from 'vue'
 import LogoMark from './LogoMark.vue'
 const props = defineProps({
   conversations: { type: Array, default: () => [] },
-  activeId: { type: [String, null], default: null },
+  activeId: { type: [String, Number, null], default: null },
   user: { type: Object, default: null },
 })
 const emit = defineEmits(['new', 'select', 'open-kb', 'delete'])
 const initial = () => (props.user?.nickname || props.user?.username || 'U').slice(0, 1).toUpperCase()
+
+// 会话搜索（纯前端过滤标题）—— 重度用户积累几十条会话后必需
+const kw = ref('')
+const filtered = computed(() => {
+  const k = kw.value.trim().toLowerCase()
+  return k ? props.conversations.filter((c) => (c.title || '').toLowerCase().includes(k)) : props.conversations
+})
 </script>
 
 <template>
@@ -25,10 +33,16 @@ const initial = () => (props.user?.nickname || props.user?.username || 'U').slic
     </button>
 
     <div class="section-label">会话历史</div>
+    <div class="search" v-if="conversations.length > 5">
+      <svg viewBox="0 0 20 20" width="13" height="13"><circle cx="9" cy="9" r="5.5" fill="none" stroke="currentColor" stroke-width="1.6"/><line x1="13.5" y1="13.5" x2="17" y2="17" stroke="currentColor" stroke-width="1.6" stroke-linecap="round"/></svg>
+      <input v-model="kw" type="text" placeholder="搜索会话…" />
+      <button v-if="kw" class="clear" @click="kw = ''">✕</button>
+    </div>
     <nav class="history">
       <p v-if="!conversations.length" class="empty-hint">还没有对话<br/><span>问一句开始吧</span></p>
+      <p v-else-if="!filtered.length" class="empty-hint">没有匹配「{{ kw }}」的会话</p>
       <div
-        v-for="c in conversations" :key="c.id"
+        v-for="c in filtered" :key="c.id"
         class="conv" :class="{ active: c.id === activeId }"
         role="button" tabindex="0"
         @click="emit('select', c.id)" @keyup.enter="emit('select', c.id)">
@@ -84,6 +98,20 @@ const initial = () => (props.user?.nickname || props.user?.username || 'U').slic
   font-size: 10.5px; color: var(--side-tx-dim); letter-spacing: .16em; margin: 20px 10px 8px;
   font-weight: 700; text-transform: uppercase;
 }
+.search {
+  display: flex; align-items: center; gap: 7px; margin: 0 2px 8px;
+  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.08);
+  border-radius: var(--r-sm); padding: 6px 10px; color: var(--side-tx-dim);
+  transition: border-color .15s;
+}
+.search:focus-within { border-color: var(--jade-500); }
+.search input {
+  flex: 1; min-width: 0; border: none; outline: none; background: transparent;
+  font-size: 12.5px; color: var(--side-tx);
+}
+.search input::placeholder { color: var(--side-tx-dim); }
+.search .clear { flex: none; font-size: 11px; color: var(--side-tx-dim); padding: 0 2px; }
+.search .clear:hover { color: #fff; }
 .history { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 2px; min-height: 0; }
 .empty-hint { font-size: 13px; color: var(--side-tx-dim); padding: 10px; text-align: center; line-height: 1.7; }
 .empty-hint span { font-size: 11.5px; opacity: .8; }
diff --git a/frontend/src/composables/useChat.js b/frontend/src/composables/useChat.js
index d5fa31f..758fe4c 100644
--- a/frontend/src/composables/useChat.js
+++ b/frontend/src/composables/useChat.js
@@ -33,9 +33,10 @@ function makeStages(intent) {
   ]
 }
 
-function newAssistant() {
+function newAssistant(question = '') {
   return reactive({
     id: uid(), role: 'assistant', status: 'thinking',
+    question,                                     // 原问题：错误时一键重试用
     intent: null, confidence: null, stages: [],
     sql: '', columns: [], rows: [],
     chartPayload: null,
@@ -155,7 +156,7 @@ export function useChat() {
     if (conv.messages.length === 0) conv.title = q.length > 20 ? q.slice(0, 20) + '…' : q
 
     conv.messages.push({ id: uid(), role: 'user', content: q })
-    const msg = newAssistant()
+    const msg = newAssistant(q)
     conv.messages.push(msg)
     sending.value = true
     persist()
@@ -178,6 +179,12 @@ export function useChat() {
 
   function applyEvent(msg, ev) {
     switch (ev.type) {
+      case 'stage':
+        // 后端起跑前的即时反馈：intent 未到时先亮一个「分析问题」步骤，避免长时间无响应感
+        if (!msg.stages.length) {
+          msg.stages = [{ key: 'intent', label: ev.message || '分析问题中', status: 'active' }]
+        }
+        break
       case 'intent':
         msg.intent = ev.intent; msg.confidence = ev.confidence
         msg.stages = makeStages(ev.intent); msg.status = 'thinking'; break
diff --git a/frontend/src/utils/export.js b/frontend/src/utils/export.js
new file mode 100644
index 0000000..2229d92
--- /dev/null
+++ b/frontend/src/utils/export.js
@@ -0,0 +1,65 @@
+// 导出工具：重度用户高频动作 —— 把结果带走（CSV / PNG / 复制文本）。
+// 不引第三方库，全部用浏览器原生能力。
+
+/** columns + 数组行 → CSV 文本（RFC4180 转义；含 UTF-8 BOM，Excel 直接打开不乱码） */
+export function toCSV(columns, rows) {
+  const esc = (v) => {
+    const s = v == null ? '' : String(v)
+    return /[",\n\r]/.test(s) ? `"${s.replace(/"/g, '""')}"` : s
+  }
+  const lines = [columns.map(esc).join(',')]
+  for (const r of rows) lines.push(r.map(esc).join(','))
+  return '\ufeff' + lines.join('\r\n')
+}
+
+/** 触发浏览器下载 */
+export function downloadFile(filename, content, mime = 'text/plain') {
+  const blob = content instanceof Blob ? content : new Blob([content], { type: mime })
+  const url = URL.createObjectURL(blob)
+  const a = document.createElement('a')
+  a.href = url
+  a.download = filename
+  document.body.appendChild(a)
+  a.click()
+  a.remove()
+  URL.revokeObjectURL(url)
+}
+
+/** dataURL（如 ECharts getDataURL 的 PNG）→ 下载 */
+export function downloadDataURL(filename, dataURL) {
+  const a = document.createElement('a')
+  a.href = dataURL
+  a.download = filename
+  document.body.appendChild(a)
+  a.click()
+  a.remove()
+}
+
+/** 复制文本到剪贴板；返回 Promise<boolean>。带 execCommand 兜底（http 演示环境无 clipboard API）。 */
+export async function copyText(text) {
+  try {
+    await navigator.clipboard.writeText(text)
+    return true
+  } catch {
+    try {
+      const ta = document.createElement('textarea')
+      ta.value = text
+      ta.style.position = 'fixed'
+      ta.style.opacity = '0'
+      document.body.appendChild(ta)
+      ta.select()
+      const ok = document.execCommand('copy')
+      ta.remove()
+      return ok
+    } catch {
+      return false
+    }
+  }
+}
+
+/** 用消息标题/时间生成安全文件名 */
+export function exportName(prefix, ext) {
+  const t = new Date()
+  const pad = (n) => String(n).padStart(2, '0')
+  return `${prefix}_${t.getFullYear()}${pad(t.getMonth() + 1)}${pad(t.getDate())}_${pad(t.getHours())}${pad(t.getMinutes())}.${ext}`
+}
diff --git a/frontend/vite.config.js b/frontend/vite.config.js
index c3e6914..db386e5 100644
--- a/frontend/vite.config.js
+++ b/frontend/vite.config.js
@@ -12,4 +12,15 @@ export default defineConfig({
     port: 5173,
     strictPort: false,
   },
+  build: {
+    // ECharts 体积大且极少变动 → 拆独立 chunk：首屏只拉业务代码，且发版后 echarts 缓存仍命中
+    rollupOptions: {
+      output: {
+        manualChunks: {
+          echarts: ['echarts/core', 'echarts/charts', 'echarts/components', 'echarts/renderers'],
+          vue: ['vue'],
+        },
+      },
+    },
+  },
 })