Tasker::Future(R)

We'll force the state into canceled as we use this to prevent rescheduling

Records the terminal state once the callback has finished. The task invokes this under its own lock — the same lock #cancel holds — so completion and cancellation are serialised without this class needing a mutex of its own. Completion never overwrites a cancel, so state == Canceled reliably means "the user cancelled; do not reschedule".

The future is holding the state for our scheduled task

As we are controlling the delay we need direct access to run_compute

We also want direct access to wait without grabbing the computed response