Wire the prod boot to issue frp-client + device leaves from the existing on-disk
P-256 CAs: NATIVE_* env vars, a file-backed KmsResolver (loads the PEM key,
validates prime256v1, never logs key material), buildFileBackedNativeCas threaded
into buildControlPlane via a nativeCas override. Fail-closed on partial NATIVE_*.
281 tests pass.
