fix: session persistence, multi-turn memory, OCR pipeline, download UX (v7)

- graph.stream() state fix: agent_state now properly accumulates node updates

- atomic session save (tempfile + os.replace)

- uploaded_file_path injection for OcrExtractor + annotation_detector

- download section always visible; refreshFromApi auto-reloads after generation

- node_start/complete unfiltered for full progress visibility

- modification_request without status=='pass' check

CLAUDE.md

@@ -262,3 +262,42 @@ validation_service/ (FastAPI, 端口 8001) — 不变
 - `ProcessSection.vue` 渲染步骤编号/标签/耗时/内容（XML 代码高亮）
 
 **Fix 5 — 消息耗时显示**: `api_server.py` `agent_complete` 事件新增 `total_duration_ms`，`SummaryCard.vue` 显示总耗时，`chat.ts` 暴露 `lastDurationMs` + `formatDuration()`
+
+
+## 更新 (v7 — 2026-05-22)
+
+### 会话持久化 & 多轮对话记忆修复
+
+**原子写入** (`backend/session.py`): `save_session` 改用 tempfile + os.replace 原子写入，防止进程崩溃时 JSON 截断导致会话损坏。
+
+**graph.stream 状态修复** (`api_server.py`): LangGraph 的 `graph.stream()`
+只产出事件，不修改传入的 `agent_state`。`_run_graph_sync` 改为手动收集每个节点的
+返回 dict 并 `agent_state.update()`，确保 done 事件到达时 agent_state 已是完整状态。
+此修复解决了第二次请求时 `current_jrxml` 为空、导致多轮对话"失忆"的问题。
+
+**save_session 调用时机**: 从 `stream_and_save` 末尾移至 `_sse_generator` 中 done 分支
+（yield `agent_complete` 之前），消除前端 `refreshFromApi()` 的竞态。
+
+### OCR 管线打通
+
+**uploaded_file_path 传递** (`api_server.py`): `_process_files` 返回的 `uploaded_paths`
+注入 `agent_state["uploaded_file_path"]`，使 `process_input` 节点的 `OcrExtractor` 字段
+精确提取和 `annotation_detector` 批注检测得以触发。此前 `uploaded_file_path` 始终为空，
+第二层 OCR 从未执行。
+
+### 前端体验改进
+
+**下载区常驻** (`Sidebar.vue`): 下载区域始终可见，无文件时显示灰色"暂无下载文件"，
+生成完成后自动出现下载链接。
+
+**侧边栏自动刷新** (`stores/session.ts`, `App.vue`): 新增 `refreshFromApi()` 方法，
+`agent_complete` 后自动从 API 重新加载会话状态，下载按钮无需手动刷新即可出现。
+
+**节点进度完整展示** (`api_server.py`): 移除 `node_complete` 事件的 SKIP_NODES 过滤，
+所有节点（包括加载会话等内部节点）的 start/complete 事件均正常发送，前端可看到
+完整流转（running → done）。
+
+### modification_request 宽松化
+
+原有 `status == "pass"` 条件去除：只要 `current_jrxml` 存在即设置
+`user_modification_request`，确保修改意图的请求能携带完整上下文。

api_server.py

@@ -166,10 +166,21 @@ def _extract_detail(node_name: str, node_state: dict) -> str:
 
 
 def _run_graph_sync(agent_state: AgentState, event_q: queue.Queue):
-    """在后台线程中运行 graph.stream()，将所有事件推入队列。"""
+    """在后台线程中运行 graph.stream()，将所有事件推入队列。
+    
+    graph.stream() 只产出事件，不修改传入的 agent_state。
+    因此需要手动收集每个节点的返回并合并到 agent_state。
+    """
     try:
         for event in _graph.stream(agent_state, stream_mode=["updates", "custom"]):
             event_q.put(event)
+            # 将节点更新合并到 agent_state
+            if isinstance(event, tuple) and len(event) == 2:
+                mode, data = event
+                if mode == "updates" and isinstance(data, dict):
+                    for node_state in data.values():
+                        if isinstance(node_state, dict):
+                            agent_state.update(node_state)
         event_q.put(("done", {"reason": "graph_completed"}))
     except Exception as exc:
         event_q.put(("error", {
@@ -178,7 +189,7 @@ def _run_graph_sync(agent_state: AgentState, event_q: queue.Queue):
         }))
 
 
-async def _sse_generator(agent_state: AgentState) -> str:
+async def _sse_generator(agent_state: AgentState, session_id: str = "") -> str:
     """SSE 事件生成器 —— 在后台线程运行图，异步产出 SSE 字符串。"""
     global _current_event_queue, _step_counter
 
@@ -205,6 +216,8 @@ async def _sse_generator(agent_state: AgentState) -> str:
             if kind == "done":
                 _current_event_queue = None
                 total_ms = round((time.time() - t_start) * 1000)
+                if session_id:
+                    save_session(session_id, agent_state)
                 yield _sse_line("agent_complete", {
                     "reason": "done",
                     "intent": agent_state.get("intent", ""),
@@ -233,13 +246,12 @@ async def _sse_generator(agent_state: AgentState) -> str:
                 mode, data = item
                 if mode == "updates":
                     for node_name, node_state in data.items():
-                        if node_name not in SKIP_NODES:
+                        detail = _extract_detail(node_name, node_state)
-                            detail = _extract_detail(node_name, node_state)
+                        yield _sse_line("node_complete", {
-                            yield _sse_line("node_complete", {
+                            "node": node_name,
-                                "node": node_name,
+                            "label": NODE_LABELS.get(node_name, node_name),
-                                "label": NODE_LABELS.get(node_name, node_name),
+                            "detail": detail,
-                                "detail": detail,
+                        })
-                            })
                 elif mode == "custom":
                     cd = data
                     if cd.get("type") == "stream":
@@ -500,9 +512,11 @@ async def chat(session_id: str, payload: dict):
                     for line in file_result["ocr_text"].split("\n") if line.strip()]
         if ocr_rows:
             agent_state["ocr_elements"] = ocr_rows
+    if file_result.get("uploaded_paths"):
+        agent_state["uploaded_file_path"] = file_result["uploaded_paths"][0]
 
     # ── 设置本轮输入 ──
-    if agent_state.get("current_jrxml") and agent_state.get("status") == "pass":
+    if agent_state.get("current_jrxml"):
         agent_state["user_modification_request"] = full_prompt
 
     agent_state["user_input"] = full_prompt
@@ -519,12 +533,9 @@ async def chat(session_id: str, payload: dict):
     # ── 返回 SSE 流 ──
     async def stream_and_save():
         final_state = None
-        async for sse_chunk in _sse_generator(agent_state):
+        async for sse_chunk in _sse_generator(agent_state, session_id):
             yield sse_chunk
 
-        # 图执行完成后保存会话状态
-        save_session(session_id, agent_state)
-
     return StreamingResponse(
         stream_and_save(),
         media_type="text/event-stream",

backend/session.py

@@ -6,6 +6,7 @@
 import json
 import os
 import uuid
+import tempfile
 from datetime import datetime, timezone
 from pathlib import Path
 from typing import Optional
@@ -64,7 +65,7 @@ def load_session(session_id: str) -> Optional[dict]:
 
 
 def save_session(session_id: str, agent_state: dict, session_name: str = ""):
-    """将会话状态保存（更新）至磁盘。"""
+    """将会话状态原子保存至磁盘（temp file + rename，避免崩溃时截断）。"""
     _ensure_dir()
     fp = _session_path(session_id)
     data = {}
@@ -82,8 +83,19 @@ def save_session(session_id: str, agent_state: dict, session_name: str = ""):
         data["created_at"] = data["updated_at"]
     data["agent_state"] = agent_state
 
-    with open(fp, "w", encoding="utf-8") as f:
+    # 原子写入：先写临时文件，再 replace，避免崩溃时截断 JSON
-        json.dump(data, f, ensure_ascii=False, indent=2)
+    tmp = tempfile.NamedTemporaryFile(
+        mode="w", suffix=".json", delete=False,
+        dir=SESSIONS_DIR, encoding="utf-8",
+    )
+    try:
+        json.dump(data, tmp, ensure_ascii=False, indent=2)
+        tmp.close()
+        os.replace(tmp.name, str(fp))
+    except Exception:
+        tmp.close()
+        Path(tmp.name).unlink(missing_ok=True)
+        raise
 
 
 def get_session_state(session_id: str) -> Optional[dict]:

frontend/src/App.vue

@@ -98,12 +98,12 @@ async function handleSend(text: string, files: File[]) {
         }
 
         // Refresh session sidebar data after a short delay
-        setTimeout(() => session.refreshFromState({}), 500)
+        setTimeout(() => session.refreshFromApi(), 500)
       },
       onAgentError(data) {
         chat.setError(data.error)
         chat.addMessage({ role: 'assistant', content: `执行异常: ${data.error}`, type: 'error' })
-        setTimeout(() => session.refreshFromState({}), 500)
+        setTimeout(() => session.refreshFromApi(), 500)
       },
     })
   } catch (e: any) {

frontend/src/components/Sidebar.vue

@@ -99,7 +99,7 @@ async function handleDelete() {
       </div>
     </div>
 
-    <div class="sidebar-section" v-if="session.currentJrxml || session.versions.length > 0">
+    <div class="sidebar-section">
       <div class="section-title">下载</div>
       <a
         v-if="session.currentJrxml"
@@ -109,6 +109,7 @@ async function handleDelete() {
       >
         下载最新 JRXML
       </a>
+      <div v-else class="btn-download disabled">暂无下载文件</div>
       <div v-if="session.versions.length > 1" class="version-list">
         <div class="version-list-title">历史版本</div>
         <a
@@ -181,178 +182,130 @@ async function handleDelete() {
   cursor: pointer;
   font-size: 16px;
   line-height: 1;
+  display: flex;
+  align-items: center;
+  justify-content: center;
 }
-
+.btn-icon:hover { background: #45475a; }
-.btn-icon:hover {
-  background: #45475a;
-}
 
 .session-list {
   max-height: 300px;
   overflow-y: auto;
+  padding: 0 8px;
 }
 
 .session-item {
-  padding: 8px 16px;
-  cursor: pointer;
   display: flex;
   justify-content: space-between;
   align-items: center;
-  font-size: 13px;
+  padding: 8px 8px;
+  border-radius: 6px;
+  cursor: pointer;
   transition: background 0.15s;
 }
-
+.session-item:hover { background: #313244; }
-.session-item:hover {
+.session-item.active { background: #45475a; }
-  background: #313244;
-}
-
-.session-item.active {
-  background: #45475a;
-  border-left: 3px solid #cba6f7;
-  padding-left: 13px;
-}
 
 .session-name {
+  font-size: 13px;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
-  max-width: 150px;
+  flex: 1;
 }
-
 .session-time {
   font-size: 11px;
   color: #6c7086;
+  margin-left: 8px;
   flex-shrink: 0;
 }
 
 .btn-delete {
   display: block;
-  width: calc(100% - 32px);
+  width: calc(100% - 16px);
-  margin: 8px 16px 0;
+  margin: 8px 8px 0;
-  padding: 6px 12px;
+  padding: 6px 0;
-  border: 1px solid #f38ba8;
+  border: 1px solid #45475a;
-  background: transparent;
+  background: none;
   color: #f38ba8;
-  border-radius: 6px;
+  border-radius: 4px;
   cursor: pointer;
   font-size: 12px;
+  text-align: center;
 }
-
+.btn-delete:hover { background: #45475a; }
-.btn-delete:hover {
-  background: #f38ba8;
-  color: #1e1e2e;
-}
 
 .quick-actions {
   display: flex;
-  gap: 6px;
+  gap: 8px;
   padding: 0 16px;
 }
 
 .btn-action {
   flex: 1;
-  padding: 6px 8px;
+  padding: 6px 0;
   border: 1px solid #45475a;
-  background: #313244;
+  border-radius: 4px;
-  color: #cdd6f4;
-  border-radius: 6px;
   cursor: pointer;
   font-size: 12px;
-  transition: background 0.15s, border-color 0.15s;
+  color: #cdd6f4;
-}
+  background: none;
-
+  transition: background 0.15s;
-.btn-action:hover:not(:disabled) {
-  background: #45475a;
-}
-
-.btn-action:disabled {
-  opacity: 0.4;
-  cursor: not-allowed;
-}
-
-.btn-preview {
-  border-color: #89b4fa;
-}
-
-.btn-preview:hover:not(:disabled) {
-  background: #89b4fa;
-  color: #1e1e2e;
-}
-
-.btn-undo {
-  border-color: #f9e2af;
-}
-
-.btn-undo:hover:not(:disabled) {
-  background: #f9e2af;
-  color: #1e1e2e;
-}
-
-.btn-reset {
-  border-color: #f38ba8;
-}
-
-.btn-reset:hover:not(:disabled) {
-  background: #f38ba8;
-  color: #1e1e2e;
 }
+.btn-action:hover:not(:disabled) { background: #45475a; }
+.btn-action:disabled { opacity: 0.4; cursor: not-allowed; }
+.btn-preview { border-color: #a6e3a1; color: #a6e3a1; }
+.btn-undo { border-color: #f9e2af; color: #f9e2af; }
+.btn-reset { border-color: #f38ba8; color: #f38ba8; }
 
 .btn-download {
   display: block;
-  padding: 8px 16px;
+  margin: 4px 16px;
-  color: #a6e3a1;
+  padding: 8px 0;
+  background: #cba6f7;
+  color: #1e1e2e;
+  text-align: center;
+  border-radius: 4px;
   text-decoration: none;
   font-size: 13px;
+  font-weight: 600;
+  cursor: pointer;
 }
-
+.btn-download:hover { background: #b4befe; }
-.btn-download:hover {
+.btn-download.disabled {
   background: #313244;
+  color: #6c7086;
+  cursor: not-allowed;
+  font-weight: 400;
 }
 
 .version-list {
-  padding: 4px 16px 8px;
+  margin-top: 8px;
+  padding: 0 16px;
 }
 
 .version-list-title {
   font-size: 11px;
   color: #6c7086;
   margin-bottom: 4px;
-  padding-top: 8px;
-  border-top: 1px solid #313244;
 }
 
 .version-item {
   display: flex;
   justify-content: space-between;
-  align-items: center;
   padding: 4px 0;
   font-size: 12px;
   color: #a6adc8;
   text-decoration: none;
 }
-
+.version-item:hover { color: #cba6f7; }
-.version-item:hover {
+.version-time { font-size: 11px; color: #6c7086; }
-  color: #cdd6f4;
-}
-
-.version-label {
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-}
-
-.version-time {
-  font-size: 11px;
-  color: #6c7086;
-  flex-shrink: 0;
-  margin-left: 8px;
-}
 
 .sidebar-footer {
   margin-top: auto;
   padding: 12px 16px;
   font-size: 11px;
-  color: #6c7086;
+  color: #585b70;
   border-top: 1px solid #313244;
 }
 </style>

frontend/src/stores/session.ts

@@ -63,6 +63,19 @@ export const useSessionStore = defineStore('session', () => {
     versions.value = []
   }
 
+  async function refreshFromApi() {
+    if (!currentId.value) return
+    try {
+      const data = await api.getSession(currentId.value)
+      const state = data.agent_state
+      currentJrxml.value = state.current_jrxml || ''
+      versions.value = state.jrxml_versions || []
+      historyStates.value = state.history_states || []
+    } catch (e) {
+      console.error('刷新会话状态失败:', e)
+    }
+  }
+
   function refreshFromState(agentState: Record<string, any>) {
     currentJrxml.value = agentState.current_jrxml || currentJrxml.value
     versions.value = agentState.jrxml_versions || versions.value
@@ -72,6 +85,6 @@ export const useSessionStore = defineStore('session', () => {
   return {
     sessions, currentId, currentName, versions, historyStates, currentJrxml,
     hasJrxml, hasHistory, sortedSessions, currentSession,
-    loadSessions, createSession, switchSession, deleteCurrent, refreshFromState,
+    loadSessions, createSession, switchSession, deleteCurrent, refreshFromState, refreshFromApi,
   }
 })