The personal-config smoke asserted that `$DSH_HOME/.env` feeds a `!!js`
expression in the personal `config.yaml` — the hoist this branch removed so
`credentials-local` can own that document and keep stored keys rotatable.
Seed both layers instead and let one expression separate them: the welcome
prefers the personal variable, so it can only render the invoking directory's
value while the harness home's `.env` stays out of `process.env`. The negative
that made the removal worth doing is now asserted in the assembled
application, not just in the provider's unit tests.
Yichen Jiang
52ae578982