Fix "pure dark mode" setting visibility

In case the apps theme mode was never changed, the "mui-mode" was never set.
This lead to the "pure black mode" setting to never be visible.

src/modules/core/utils/MediaQuery.tsx

@@ -11,7 +11,6 @@ import { Breakpoint, SxProps, Theme } from '@mui/material/styles';
 import { useCallback, useState } from 'react';
 import { getCurrentTheme } from '@/modules/theme/services/ThemeCreator.ts';
 import { ThemeMode } from '@/modules/theme/contexts/AppThemeContext.tsx';
-import { AppStorage } from '@/lib/storage/AppStorage.ts';
 import { useResizeObserver } from '@/modules/core/hooks/useResizeObserver.tsx';
 
 export class MediaQuery {
@@ -90,9 +89,7 @@ export class MediaQuery {
         return prefersDarkMode ? ThemeMode.DARK : ThemeMode.LIGHT;
     }
 
-    static getThemeMode(): Exclude<ThemeMode, 'system'> {
-        const themeMode = AppStorage.local.getItem('mui-mode') as ThemeMode;
-
+    static getThemeMode(themeMode: ThemeMode): Exclude<ThemeMode, 'system'> {
         const isSystemMode = themeMode === ThemeMode.SYSTEM;
         if (isSystemMode) {
             return this.getSystemThemeMode();

src/modules/settings/screens/Appearance.tsx

@@ -52,7 +52,7 @@ export const Appearance = () => {
         makeToast(t('global.error.label.failed_to_save_changes'), 'error', getErrorMessage(e)),
     );
 
-    const isDarkMode = MediaQuery.getThemeMode() === ThemeMode.DARK;
+    const isDarkMode = MediaQuery.getThemeMode(actualThemeMode) === ThemeMode.DARK;
 
     if (loading) {
         return <LoadingPlaceholder />;