Fix interrupting ACP threads and CC cancellation (#35752)

Fixes a bug where generation wouldn't continue after interrupting the
agent, and improves CC cancellation so we don't display "[Request
interrupted by user]"

Release Notes:

- N/A

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Co-authored-by: Cole Miller <cole@zed.dev>
bd1c26cb5bAgus Zubiaga committed on 8/7/2025, 1:55:17 AM· committed by GitHubparent1907b16
2 files changedLine totals unavailable