[FEATURE] Agent Teams: Forking Warm Sessions + init phase for Teammates

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When I have a long-running team session, I think I'm seeing cases where "codebase expert" is spawned, handles some tasks, then gets cleaned up. If we need another session with codebase expert later on, a fresh one is spawned, and it must reingest the relevant parts of the codebase.

Proposed Solution

What if we could specify an "init" phase for teammates where they can gather context, and then any instances of that teammate are forked from that "warm" session? Goal being avoiding spawning brand new instances that need to re-digest the frontmatter/init context. Then I could warm up an "Expert teammate in xyz modules" and fork that session. Maybe I'm describing something that is possible through other means, just thought I'd throw it out there.

Alternative Solutions

_No response_

Priority

Low - Nice to have

Feature Category

Other

Use Case Example

I have a large task that I may iterate on for a while in the same session, because team lead is good about using subagents to keep its context clean. It will require revisiting parts of the code after feedback/bugs are reported by me. I would like to be able to fork from a session that already understands the parts of the code.

Additional Context

_No response_