Two private formatters mapped the canonical server resolution label to
display text (media_quality_labels, media_version) with edge-case
drift, and several single-consumer helpers added indirection without
callers:
- add shared resolutionDisplayLabel in resolution_label.dart and
migrate MediaVersion.displayLabel and the quality-label builder to it
- drop the resolutionLabelFromHeight compat re-export from
jellyfin_mappers (no remaining consumers) and its stale doc note
- delete TraktCatalogSource.membershipKeysFor, byte-identical to the
CatalogWatchlistMachinery default
- derive the rating sheet backend label from
MediaBrowserDialect.productName instead of a hardcoded switch
- inline EndpointFailoverManager into failover_http_client.dart, its
only importer, and remove endpoint_failover_interceptor.dart
edde746