## Why
MCP startup notifications from unrelated threads could create TUI event channels, allowing subsequent approval requests from those threads to appear in the current session.
## What changed
Check the parent of an untracked subagent before accepting its MCP startup notifications. Read thread metadata with bounded retries for threads that are not yet found or loaded, and ignore notifications unless the parent belongs to the TUI.
Share thread ownership checks across notification and approval routing, including side threads.
## Testing
Extend approval-routing coverage to verify that owned subagent approvals are preserved both before thread-start notifications and after MCP startup notifications, while unrelated threads do not create event channels or display approval prompts.
GitOrigin-RevId: 6f78f237f7441aadf10b491ed191357df75c3a6a
Eric Traut
f365d5754b