Integrate branding and theme settings with database

- Update BrandingPage to save settings to database instead of localStorage
- Add public settings endpoint for galleries to fetch branding/theme
- Update GalleryView to apply branding settings in footer
- Apply theme settings from database to gallery pages
- Support event-specific themes that override global settings
- Ensure watermark and all branding settings are stored in database

backend/server.js

@@ -78,6 +78,7 @@ app.use('/api/events', eventRoutes);
 app.use('/api/gallery', galleryRoutes);
 app.use('/api/admin', adminRoutes);
 app.use('/api/admin/auth', adminAuthRoutes);
+app.use('/api/public/settings', require('./src/routes/publicSettings'));
 
 // Error handling middleware
 app.use((err, req, res, next) => {