[FEATURE] expose subagent ID to session agent

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

I have a skill I use when developing an agent workflow to review recent sessions, and the pattern I usually invoke this in is:

1. start session
2. ask it to start 1 or more subagents to use some /skill or plugin or something
3. have main session wait for them to finish, then use /review-sessions skill to look for patterns of agent friction/wasteful token usage/errors/confusion etc.

the main session always has to spend 3-5 turns finding the correct subagent conversations. It'd be nice if the IDs of them were exposed to it so it could look them up directly w/o having to look for ones that had similar runtime etc.

Proposed Solution

tell parent agent the IDs of the subagents it starts

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

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Additional Context

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