Add unit tests for handwritten and declarative validation, controller
logic, metrics, table printer output, controller-manager registration,
etcd storage round-trip, and an integration test for the full RPSR
lifecycle. Also add an e2e test exercising the DRA test driver with
RPSR and the example manifest.
Implement the RPSR controller that watches ResourcePoolStatusRequest
objects and aggregates pool status from DRA drivers. Add the API server
registry (strategy, storage), handwritten validation, RBAC bootstrap
policy for the controller, kube-controller-manager wiring, table
printer columns, and storage factory registration.
