wip: making themes more dynamic and easy to add

src/lib/stores/theme.svelte.ts

@@ -1,6 +1,7 @@
 import { browser } from '$app/environment';
 
 type Theme = 'light' | 'dark' | 'system';
+type ResolvedTheme = 'light' | 'dark';
 
 class ThemeStore {
 	current = $state<Theme>('system');
@@ -35,6 +36,12 @@ class ThemeStore {
 		}
 	}
 
+	getResolvedTheme(): ResolvedTheme {
+		const isDark = this.current === 'dark' ||
+			(this.current === 'system' && window.matchMedia('(prefers-color-scheme: dark)').matches);
+		return isDark ? 'dark' : 'light';
+	}
+
 	toggle() {
 		// Cycle through: light -> dark -> system -> light
 		if (this.current === 'light') {