Fix theme preset switching issue

- Fix preset theme selection in BrandingPage
- Add debug logging to track theme changes
- Properly update currentTheme state when preset is selected
- Match saved theme to preset on initialization
- Remove unused imports

frontend/src/components/admin/ThemeCustomizer.tsx

@@ -36,6 +36,7 @@ export const ThemeCustomizer: React.FC<ThemeCustomizerProps> = ({
 
   const handlePresetSelect = (presetKey: string) => {
     const preset = PRESET_THEMES[presetKey];
+    console.log('Selecting preset:', presetKey, preset); // Debug log
     if (preset) {
       setSelectedPreset(presetKey);
       setLocalTheme(preset.config);
@@ -49,6 +50,7 @@ export const ThemeCustomizer: React.FC<ThemeCustomizerProps> = ({
   };
 
   const handleApply = () => {
+    console.log('Applying theme:', { ...localTheme, customCss }); // Debug log
     onChange({ ...localTheme, customCss });
   };