## Summary
- Align Go agent logs access with the Python behavior by checking tenant
access to the target agent instead of requiring the token to be bound
to that agent.
- Marshal canvas lifecycle event payloads safely so non-serializable
inputs do not break Thinking expansion in the UI.
## Testing
- `CGO_ENABLED=0 go test -count=1 -v -run
"Handler|Attachment|Logs|Chatbot|Agentbot|BuildWorkflow|NodeLifecycle|VarRef|Resolve|Extract"./internal/handler/
./internal/agent/canvas/...` PASS