Wake the leader when teams go idle with pending tasks

[jonatascastro12]

Summary

• add a deduplicated leader wake-up prompt when workers report idle while no tasks are in progress but pending tasks remain
• make task completion/failure notifications explicitly tell the leader to keep going when work is stalled behind blockers or assignments
• cover the stalled-team wake-up path in the smoke tests and document the behavior

Testing

• npm run check
• npm run smoke-test