Follow-up to #2955. That PR split the SettingsService god-object and made SettingsModule a @Global provider of SettingsDataService, but left the module-level forwardRef wiring (and the one constructor cycle it called irreducible) in place. With the settings cycles gone, those workarounds are now removable.

What this does

• Vestigial drops — the Plex, TMDB, TVDB, Jellyfin and Emby modules each only read settings via the @Global SettingsDataService, so their forwardRef(() => SettingsModule) import is dropped entirely.
• SettingsModule — its nine forwardRef(() => XApiModule) imports become plain imports, now that no API module imports SettingsModule back.
• The last service cycle — MediaServerFactory ↔ MediaServerSwitchService is broken by extracting the in-progress flag into a zero-dependency MediaServerSwitchState holder: the factory reads it, the switch service writes it, neither depends on the other.
• The guard — the data-only testSetup() moves onto SettingsDataService (kept as a delegating wrapper on SettingsOperationsService), so MediaServerSetupGuard reads it from the @Global service and MediaServerModule drops its SettingsModule import.

Result

The only remaining forwardRefs are the genuine, pre-existing CollectionsModule ↔ RulesModule domain cycle (RulesService injects CollectionsService; CollectionsController reads the rule executor's processing state), untouched here and a clean candidate for the same flag-extraction pattern in a follow-up.

Behaviour

Unchanged. The switch/conflict semantics, the public testSetup API, and the media-server setup guard all behave as before — only their wiring moved.

Validation

build (tsc) ✓ · 75 suites / 1336 tests ✓ · lint ✓ · prettier ✓ · full Nest DI context boots with the rewired providers (no circular dependency) ✓.