fix(server): subagent threads settle with their parent instead of sweeping on their own#19665

Merge branch 'main' into fix/subagent-settle-with-parent

fix(server): combine queued settlement sweeps

fix(server): drain subagents when their parent settles

Merge main for parent-driven subagent settlement

fix(server): a failed parent read no longer runs the settle script for a subagent

fix(server): subagent threads settle with their parent instead of sweeping on their own