stop <id> returns 'Session not found' for a session that list/status resolve as running

[doink-kindo]

Summary

agentctl stop <id> (and stop <id> --force) fails with Session not found: <full-uuid> for a session that agentctl status <id> and agentctl list -a both report as running. The short id resolves to the correct full uuid (it's echoed in the error), but the stop path can't find the session to terminate it. Net effect: no clean way to stop the agent via the CLI — had to kill -TERM the underlying claude PID directly.

Repro (observed 2026-07-06)

Launched a claude-code session:

$ agentctl list -a | grep 829a9101
829a9101  running  claude-code  claude-fable-5   ~/code/mono-auto-ENG-10879   79911  2m ago  EXECUTE THIS PROCEDURE...

$ agentctl status 829a9101
ID     829a9101
Status running
PID    79911
...

$ agentctl stop 829a9101 --force
Session not found: 829a9101-c228-4d15-b153-bc816f954658

$ agentctl stop 829a9101        # retry, no --force
Session not found: 829a9101-c228-4d15-b153-bc816f954658
# ...but list -a STILL shows it running with PID 79911

$ kill -TERM 79911              # only way to actually stop it

Expected

stop <id> terminates the session that status/list resolve for the same id (or at least returns a non-misleading error).

Actual

status/list find the session by short id and report it running; stop resolves the same short id to the full uuid but then reports Session not found, leaving the process running. The lookup path used by stop appears inconsistent with the one used by status/list.

Impact

Coordinators can't reliably stop a running agent — forced to kill the OS PID out-of-band, which risks leaving agentctl's session store in a stale running state.

Environment

• host: ms's Mac Studio (Darwin arm64)
• adapter: claude-code, model claude-fable-5
• launched via agentctl launch claude-code ... --cwd <existing-worktree>