## Summary
Sets `WOODPECKER_BACKEND_K8S_PRIORITY_CLASS: power` on the Woodpecker agent so all CI pipeline pods are scheduled with the `power` PriorityClass (value 100, preemptionPolicy: Never).
This means pipeline pods can be evicted when the cluster is under pressure but won't preempt other workloads.
## Dependency
Requires the `power` PriorityClass to exist on the cluster — deploy PR #174 (priority-classes app) first.
## Test plan
- Trigger a pipeline run and confirm pods are created with `priorityClassName: power`
- `kubectl get pod -n woodpecker -o jsonpath='{.items[*].spec.priorityClassName}'`
Reviewed-on: #175
unkinben