feat: add unified Settings dialog (#18)

src/app/services/translation-service.ts

@@ -50,6 +50,13 @@ export interface AppTranslations {
 		showWeekNumbers: string;
 		close: string;
 		selectLanguage: string;
+		selectTheme: string;
+		themeOptions: {
+			system: string;
+			light: string;
+			dark: string;
+		};
+		systemAppearance: string;
 	};
 	rules: {
 		title: string;
@@ -307,6 +314,7 @@ export class TranslationService {
 		'app.language',
 		this.getBrowserLanguage(),
 		this.injector,
+		0,
 	);
 
 	public readonly tr = computed<AppTranslations>(() => {