Define a Crossplane Composition with a pipeline function to provision an RDS instance plus a SecretsManager secret and expose connection details as a composite resource claim

Steps

1. Define a CompositeResourceDefinition (XRD) with a spec.versions entry that declares the composite resource schema including database engine, instance class, and a connectionSecretToRef field for the output secret
2. Create a Composition that references the XRD and specifies mode: Pipeline in the spec; add a pipeline step that uses the function-patch-and-transform function to map composite resource fields to the managed resource fields of an RDS DBInstance
3. Add a second pipeline step that uses a function to create an AWS SecretsManager Secret managed resource; use a patch to copy the RDS endpoint output from the DBInstance status into the Secret's stringData via a from-field-path patch
4. Configure the Composition's writeConnectionSecretsToNamespace to extract the RDS username, password, and endpoint from the managed resource's status.atProvider and write them as a Kubernetes Secret in the claim namespace
5. Add a readinessCheck block on the DBInstance managed resource that waits for status.atProvider.dbInstanceStatus to equal available before the composite resource reports Ready=True
6. Use a usage resource or Composition-level dependencies to prevent deletion of the RDS instance while the Secret resource still exists, enforcing teardown order