Added dashboard page layout & sites overview

frontend/src/utils/effectiveTheme.ts

@@ -0,0 +1,9 @@
+import type { Theme } from '@/components/theme-provider';
+
+export function getEffectiveTheme(theme: Theme): 'light' | 'dark' {
+    return theme === 'system'
+        ? window.matchMedia('(prefers-color-scheme: dark)').matches
+            ? 'dark'
+            : 'light'
+        : theme;
+}