fix: langfuse v3 import path (langfuse.decorators langfuse)

backend/agent/tools/data_retrieval_tool.py

@@ -8,7 +8,7 @@ import json
 import logging
 import time
 
-from langfuse.decorators import observe
+from langfuse import observe
 
 from langchain_core.tools import tool
 from pydantic import BaseModel, Field
@@ -159,7 +159,7 @@ async def _execute_single_search(
                 (first_p.get("description_text") or "")[:100],
             )
 
-        from langfuse.decorators import langfuse_context
+        from langfuse import langfuse_context
         langfuse_context.update_current_observation(
             input={
                 "description": item.description[:200] if item.description else None,

backend/agent/tools/product_search_helpers.py

@@ -2,7 +2,7 @@ import logging
 import os
 import time
 
-from langfuse.decorators import observe
+from langfuse import observe
 
 from common.embedding_service import create_embedding_async