The old $DSH_HOME/config.yaml personal overlay returns under the profile
scheme's filename: machine-local preferences that apply to every profile,
loaded after the profile's own cordis.patch.yml (so the home layer outranks
it) and before --patch overlays and flag patches. Both user layers are
hot-reloaded on long-lived surfaces and shown in --dump-config with their
own provenance labels; the built-bin e2e covers the home layer landing live.