Implement autobackup-operator controllers, tests, CI and packaging

PVCs and CloudNativePG Clusters need S3 buckets and backup schedules
provisioned consistently. This operator watches the
backups.unkin.net/{schedule,destination} annotations on those objects and
provisions everything needed to back them up, with no new CRDs.

- Add a PVC controller that provisions cephrgw ObjectStoreUser/Bucket/BucketAccess,
  auto-generates a restic repo-password Secret and creates a k8up Schedule scoped
  to the PVC via spec.backup.volumes[].persistentVolumeClaim.claimName.
- Add a CNPG Cluster controller that provisions the same bucket stack, idempotently
  patches spec.backup.barmanObjectStore (leaving a user-set destinationPath alone
  with a Warning event) and creates a ScheduledBackup.
- Resolve destinations through a ConfigMap lookup table; requeue until the
  BucketAccess is Ready before creating schedule resources; own-reference created
  resources and retain bucket data by default.
- Add schedule-mapping helpers (k8up 5-field/shortcut pass-through, CNPG 6-field
  seconds-first) and deterministic, length-bounded name derivation.
- Add unit tests (schedule mapping, name derivation, destination resolution) and
  envtest controller tests for both paths, wiring the external CRDs into envtest.
- Add kubebuilder-generated RBAC, a Dockerfile (distroless/nonroot), Woodpecker
  lint/test/build pipelines and a tag-triggered image push to the artifactapi
  docker-internal registry, plus a version-bump Makefile and deploy manifests.

vendor/github.com/evanphx/json-patch/v5/errors.go

@@ -0,0 +1,38 @@
+package jsonpatch
+
+import "fmt"
+
+// AccumulatedCopySizeError is an error type returned when the accumulated size
+// increase caused by copy operations in a patch operation has exceeded the
+// limit.
+type AccumulatedCopySizeError struct {
+	limit       int64
+	accumulated int64
+}
+
+// NewAccumulatedCopySizeError returns an AccumulatedCopySizeError.
+func NewAccumulatedCopySizeError(l, a int64) *AccumulatedCopySizeError {
+	return &AccumulatedCopySizeError{limit: l, accumulated: a}
+}
+
+// Error implements the error interface.
+func (a *AccumulatedCopySizeError) Error() string {
+	return fmt.Sprintf("Unable to complete the copy, the accumulated size increase of copy is %d, exceeding the limit %d", a.accumulated, a.limit)
+}
+
+// ArraySizeError is an error type returned when the array size has exceeded
+// the limit.
+type ArraySizeError struct {
+	limit int
+	size  int
+}
+
+// NewArraySizeError returns an ArraySizeError.
+func NewArraySizeError(l, s int) *ArraySizeError {
+	return &ArraySizeError{limit: l, size: s}
+}
+
+// Error implements the error interface.
+func (a *ArraySizeError) Error() string {
+	return fmt.Sprintf("Unable to create array of size %d, limit is %d", a.size, a.limit)
+}