Not paused, no breakpoint in the eligible set — claim normally.
Paused with no step allowance — claim nothing, notify nobody.
Paused with a step allowance — the caller may claim taskIDs this pass (after consuming the
marker CAS-style; a lost consume means another instance is stepping).
An eligible task has a breakpoint — the caller should pause the graph (CAS), announce
BreakpointHit, and claim nothing this pass.
What the claim gate decided for one graph on one pass.