Is your feature request related to a problem? Please describe.

Yes, I have to persist intermediate messages generated by deep-agent's subagents to database, but the message time is missing.

Describe the solution you'd like

When creating a new schema.Message or schema.AgenticMessage by eino framework, the create time can be recorded by a message field.

Describe alternatives you've considered

I can find all new messages by using callbacks before and after calling LLMs, and record current time, but it's not that elegent and can cause performance problems.

Additional context

Please consider my request seriously.