## Summary
Cancelling an inline review could leave the TUI stuck in MCP startup
state, so subsequent `/review` commands were rejected as though another
task were still running. Specifically, the child’s “Starting MCP
servers” event was incorrectly forwarded to the parent TUI, so the
parent was marking itself as busy.
This keeps delegate-session MCP startup events inside the delegate
instead of exposing them as parent-session state.
## Reproduction
Here's the before -- notice that after I cancel the first review, I'm
prevented from running `/review` again:
https://github.com/user-attachments/assets/571a0793-3253-4bcc-8f10-3782d176162f
And the after -- notice that after I cancel, I can immediately start a
new `/review`:
https://github.com/user-attachments/assets/dd98b1d7-6a71-4a1f-a4b2-3295bc4848e5
bce481fdcb