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

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)
-                            yield _sse_line("node_complete", {
-                                "node": node_name,
-                                "label": NODE_LABELS.get(node_name, node_name),
-                                "detail": detail,
-                            })
+                        detail = _extract_detail(node_name, node_state)
+                        yield _sse_line("node_complete", {
+                            "node": node_name,
+                            "label": NODE_LABELS.get(node_name, node_name),
+                            "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",