fix: Critical pipeline ID sequencing bug

- Fixed pipelines not appearing in /sessions/{id}/pipelines endpoint
- Root cause: _create_pipeline_record called AFTER session update
- Solution: Call _create_pipeline_record FIRST (adds pipeline_id to dict), THEN update session
- Now proposed_pipeline in MongoDB includes pipeline_id
- Pipeline status updates now work correctly (pipeline_id is always present)
- Fixes empty pipelines array in API response

api_routes_v2.py

@@ -1141,9 +1141,10 @@ async def chat_unified(
                     prefer_bedrock=bool(prefer_bedrock),
                 )
 
-                session_manager.update_session(chat_id, {"proposed_pipeline": pipeline, "state": "pipeline_proposed"})
-                # V3: Create pipeline record in S3 and MongoDB
+                # V3: Create pipeline record in S3 and MongoDB (adds pipeline_id to dict)
                 pipeline_id = _create_pipeline_record(chat_id, pipeline, status="proposed", created_from="request")
+                # Now update session with pipeline that includes pipeline_id
+                session_manager.update_session(chat_id, {"proposed_pipeline": pipeline, "state": "pipeline_proposed"})
 
                 pipeline_name = pipeline.get("pipeline_name", "Document Processing")
                 steps_list = pipeline.get("pipeline_steps", [])
@@ -1202,9 +1203,10 @@ async def chat_unified(
                         file_path=session.get("current_file"),
                         prefer_bedrock=bool(prefer_bedrock)
                     )
-                    session_manager.update_session(chat_id, {"proposed_pipeline": new_pipeline, "state": "pipeline_proposed"})
-                    # V3: Create pipeline record for edited pipeline
+                    # V3: Create pipeline record for edited pipeline (adds pipeline_id)
                     pipeline_id = _create_pipeline_record(chat_id, new_pipeline, status="proposed", created_from="edit")
+                    # Now update session with pipeline that includes pipeline_id
+                    session_manager.update_session(chat_id, {"proposed_pipeline": new_pipeline, "state": "pipeline_proposed"})
 
                     formatted = format_pipeline_for_display(new_pipeline)
                     friendly = formatted + f"\n\n```json\n{json.dumps(new_pipeline, indent=2)}\n```"
@@ -1556,9 +1558,10 @@ async def chat_unified_stream(
                         file_path=session_local.get("current_file"),
                         prefer_bedrock=bool(prefer_bedrock)
                     )
-                    session_manager.update_session(chat_id, {"proposed_pipeline": new_pipeline, "state": "pipeline_proposed"})
-                    # V3: Create pipeline record for edited pipeline  
+                    # V3: Create pipeline record for edited pipeline (adds pipeline_id)
                     pipeline_id = _create_pipeline_record(chat_id, new_pipeline, status="proposed", created_from="edit")
+                    # Now update session with pipeline that includes pipeline_id
+                    session_manager.update_session(chat_id, {"proposed_pipeline": new_pipeline, "state": "pipeline_proposed"})
                     formatted = format_pipeline_for_display(new_pipeline)
                     friendly = formatted + f"\n\n```json\n{json.dumps(new_pipeline, indent=2)}\n```"
                     _add_and_mirror_message(chat_id, "assistant", friendly)