message: Code cleanup
  Fix return type annotation and simplify method implementations.
diff: @@ -46,7 +46,7 @@ export default class ManagerSettings {
  }
  - private async save(): Promise<R2Error | void> {
  + private async save(): Promise<void> {
  await ManagerSettings.DEXIE_STORE.save(ManagerSettings.CONTEXT);
  }
  @@ -158,21 +158,13 @@ export default class ManagerSettings {
  }
  public async setDefaultGame(defaultGame: Game | undefined) {
  - if (defaultGame === undefined) {
  - ManagerSettings.CONTEXT.global.defaultGame = undefined;
  - } else {
  - ManagerSettings.CONTEXT.global.defaultGame = defaultGame.internalFolderName;
  - }
  - return await this.save();
  + ManagerSettings.CONTEXT.global.defaultGame = defaultGame?.internalFolderName;
  + await this.save();
  }
  public async setDefaultStorePlatform(storePlatform: StorePlatform | undefined) {
  - if (storePlatform === undefined) {
  - ManagerSettings.CONTEXT.global.defaultStore = undefined;
  - } else {
  ManagerSettings.CONTEXT.global.defaultStore = storePlatform;
  - }
  - return await this.save();
  + await this.save();
  }
  public async setGameSelectionViewMode(viewMode: GameSelectionViewMode) {
  