[FEAT] Saves subAgentId and subAgentName to the database

[lzj960515]

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

Currently, the subAgentId and subAgentName are output during the stream process, which is good. However, when loading historical messages, the messages cannot be filtered because the subAgentId and subAgentName are not available.

Describe alternatives you've considered

No response

Additional context

No response

Describe the thing to improve

This allows users to have the same experience as streaming when viewing historical messages.

[omeraplak]

Hey @lzj960515, Thanks! We'll check it out soon ⚡️

[omeraplak]

Hey @lzj960515 ,
Good news, I've just created a PR #786

[omeraplak]

Hey,
Released 🥳 https://voltagent.dev/docs/agents/sub-agents/#filtering-historical-conversations