Feat: add sync_dsl parameter to support synchronizing modifications to existing sessions (#5843)

When accessing the /api/v1/agents/{agent_id}/completions API, sessions
created before agent modifications retain the old DSL data. To use the
latest agent configuration (like new prompts) in historical sessions, I
added the sync_dsl parameter. It defaults to False to maintain existing
behavior and only synchronizes when set to True. If needed, a manual
synchronization API can be created to trigger the sync explicitly.

api/apps/sdk/session.py

@@ -365,6 +365,18 @@ def agent_completions(tenant_id, agent_id):
         conv = API4ConversationService.query(id=req["session_id"], dialog_id=agent_id)
         if not conv:
             return get_error_data_result(f"You don't own the session {req['session_id']}")
+        # If an update to UserCanvas is detected, update the API4Conversation.dsl
+        sync_dsl = req.get("sync_dsl", False)
+        if sync_dsl is True and cvs[0].update_time > conv[0].update_time:
+            current_dsl = conv[0].dsl
+            new_dsl = json.loads(dsl)
+            state_fields = ["history", "messages", "path", "reference"]
+            states = {field: current_dsl.get(field, []) for field in state_fields}
+            current_dsl.update(new_dsl)
+            current_dsl.update(states)
+            API4ConversationService.update_by_id(req["session_id"], {
+                "dsl": current_dsl
+            })
     else:
         req["question"] = ""
     if req.get("stream", True):