What a provider serves is its definition's (ADR 0348 clause 11): a layer
fills only the keys it asks for as ${setting:<key>}. Settle replaced any
served key a layer named, so a setting for one of a provider's files could
change what every consumer was told. influxdb on ace was the one live layer
relying on it and now serves its settings (mesh-catalog, merged first), so
grafana's data source composes byte for byte as before. UnusedSettings no
longer counts a literal served key as a place a setting lands.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
