修复追问时agent丢失：服务器重启后自动重建agent，恢复file_list用于数据加载

web/main.py

@@ -183,6 +183,8 @@ class SessionManager:
                 pass
         
         # Recover Metadata
+        session.file_list = meta.get("file_list", [])
+        session.user_requirement = meta.get("user_requirement", "")
         try:
              stat = os.stat(output_dir)
              dt = datetime.fromtimestamp(stat.st_ctime)
@@ -248,6 +250,7 @@ def run_analysis_task(session_id: str, files: list, user_requirement: str, is_fo
         return
 
     session.is_running = True
+    session.file_list = files or []
     try:
         base_output_dir = "outputs"
 
@@ -261,7 +264,7 @@ def run_analysis_task(session_id: str, files: list, user_requirement: str, is_fo
         # even if the server restarts mid-analysis
         try:
             with open(os.path.join(session_output_dir, "session_meta.json"), "w") as f:
-                json.dump({"session_id": session_id, "user_requirement": user_requirement}, f, default=str)
+                json.dump({"session_id": session_id, "user_requirement": user_requirement, "file_list": files or []}, f, default=str)
         except Exception:
             pass
 
@@ -298,8 +301,12 @@ def run_analysis_task(session_id: str, files: list, user_requirement: str, is_fo
                 else:
                     agent = session.agent
                     if not agent:
-                        print("Error: Agent not initialized for follow-up.")
-                        return
+                        # Agent lost (server restart). Recreate and run as new session
+                        # with the follow-up requirement, reusing the same output dir.
+                        print("[WARN] Agent not initialized, recreating for follow-up.")
+                        llm_config = LLMConfig()
+                        agent = DataAnalysisAgent(llm_config, force_max_rounds=False, output_dir=base_output_dir)
+                        session.agent = agent
 
                     # Wire progress callback for follow-up sessions
                     def progress_cb_followup(current, total, message):
@@ -311,11 +318,16 @@ def run_analysis_task(session_id: str, files: list, user_requirement: str, is_fo
                     agent.set_progress_callback(progress_cb_followup)
                     agent.set_session_ref(session)
 
+                    # If agent was just recreated, load data files so it has context
+                    data_files = None
+                    if not agent.data_files and session.file_list:
+                        data_files = session.file_list
+
                     result = agent.analyze(
                         user_input=user_requirement,
-                        files=None,
+                        files=data_files,
                         session_output_dir=session_output_dir,
-                        reset_session=False,
+                        reset_session=not bool(agent.conversation_history),
                         max_rounds=10,
                     )