fix(coordinator): default coordinator tasks to human control

[FourWindff]

Summary

• initialize newly created coordinator tasks with human control instead of coordinator control
• when restoring persisted tasks without a control owner, default coordinator tasks to human control and coordinated child tasks to coordinator control
• add persistence tests for the missing-controlledBy restore defaults

[brooksc]

@FourWindff Thanks for the PR. I think this is pointing at a real UX problem, but I’m working on a broader fix for coordinator/user control and will submit an updated PR.

The concern with defaulting coordinator tasks to human control is that controlledBy: human currently does more than enable user typing: it also pauses staged coordinator prompts. Those prompts are how completed sub-task updates get delivered back to the coordinator, so making human control the default can cause the coordinator to sit idle waiting for a manual release.

Sub-task sessions should still default to coordinator control. The part I want to rework is the coordinator session itself: the app should avoid injecting prompts while the user is actively typing, without requiring manual take/release control as the normal workflow.

The updated approach should make coordinator/user control more intuitive and eliminate most of the need to manually take or release control.