[FEATURE]: support for .ts agent files

[m10rten]

Feature hasn't been suggested before.

• [x] I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Hi,

Since the start of AI agents, markdown has taken the lead.

But how useful would it be if we could define agent files in typescript.

This would allow to make custom agents with behaviour hard to nail with md, such as A2A contracts with zod.

Personally would really like to see this support being added.