### grant_policy (temporal only)

The optional value is exactly one typed Fabric attribute:

```text
#fabric.switch_fixed_priority<requester_order = array<i64: ...>>
#fabric.switch_round_robin<requester_cycle = array<i64: ...>,
                           reset_requester = ...>
```

Requester ordinals are the switch input-port ordinals. The sequence is a
permutation of the complete input domain and contains no duplicate. The reset
requester of a round-robin policy occurs in its cycle. A temporal switch whose
physical connectivity admits two inputs to one output requires one exact
policy in Fabric 1.0. A switch without such fan-in must omit it. Spatial
switches must omit it.