PolicyServer replica controller

[fabriziosestito]

Description

Implement a reconciliation loop in each Policy Server replica to monitor and load policies.

References

https://github.com/kubewarden/rfc/blob/main/rfc/0022-policy-lifecycle.md#policy-server-replica-reconciler

Acceptance Criteria:

• Create a replica reconciliation loop running on all Policy Server instances
• Implement loading/unloading of policies based on PolicyRevision enabled status
• Report individual replica status back to PolicyRevision resources
• Handle policy loading errors gracefully without crashing
• Expose policy endpoints with generation numbers (/validate/{policy-name}/{generation})

[fabriziosestito]

Example of a reconciler found in the POC: https://github.com/fabriziosestito/policy-server/blob/6e84438717f2f58e71cba685bb64b2a77a3209ec/src/controller/replica_reconciler.rs#L34

[fabriziosestito]

We could use this early-stage project ktest to create a mock k8s cluster for integration tests.