refactor: migrate workflow to v2 core and archive legacy modules

db/chat_log_db.py

@@ -199,14 +199,18 @@ def get_customers(limit: int = 100) -> List[Dict]:
 
 
 def get_conversation(customer_id: str, limit: int = 200) -> List[Dict]:
-    """返回某客户的全部对话记录（按时间升序）"""
+    """返回某客户的最近对话记录（按时间升序）"""
     with _get_conn() as conn:
+        # 核心修复：先取最新的 limit 条，再按时间正序排列
         rows = conn.execute(_sql("""
-            SELECT id, direction, message, msg_type, timestamp, acc_id
-            FROM chat_logs
-            WHERE customer_id = ?
+            SELECT * FROM (
+                SELECT id, direction, message, msg_type, timestamp, acc_id
+                FROM chat_logs
+                WHERE customer_id = ?
+                ORDER BY timestamp DESC, id DESC
+                LIMIT ?
+            ) AS recent
             ORDER BY timestamp ASC, id ASC
-            LIMIT ?
         """), (customer_id, limit)).fetchall()
     return [dict(r) for r in rows]