Feature Idea: operation time based break windows

[Kobe-Kwanten]

Context

European regulations require mandatory breaks after specified periods of total operation time. For example, a vehicle may need to take a 45-minute break after no more than 4.5 hours of total operation time: [EU driving-time and rest-period rules](https://transport.ec.europa.eu/transport-modes/road/social-provisions/driving-time-and-rest-periods_en).

My current understanding is that cuOpt supports break windows defined by fixed clock times, rather than windows relative to accumulated total operation time.

Proposal

Extend break-window definitions to support constraints based on cumulative total operation time.

For example, a vehicle should take a 45-minute break after it has operated for at least 4 hours, and before it exceeds 4.5 hours of total operation time.

Does cuOpt already support this type of requirement? If so, I would appreciate guidance on how to model it.

I also have a separate requirement that the vehicle must have empty capacity during its break. This would need to be combined with the total-operation-time-based break constraint. I created a separate discussion for that requirement: [Discussion #1551](#1551).

Thank you!