Let scheduled tasks react to usage limits

[cyppe]

When one thread coordinates several agents, a usage limit can stop them mid-task. After the reset, a simple “continue” can leave the coordinating agent unsure what finished and what needs restarting.

Could scheduled tasks also trigger when:

• usage passes a chosen threshold, such as 95%;
• an account hits its limit;
• quota is available again after a fresh check?

Each trigger would send a customizable message to a chosen thread. That would let the coordinating agent ask the others to wrap up safely and save their progress, then resume with a clear explanation of what happened.

The first PR could focus on these quota events. Thread-finished and idle triggers could follow later.

Would you be open to a small PR in this direction?

Related: Scheduled Prompts and pausing automations and queues.