Add default theme management to branding settings and admin interface

server/routes/branding.js

@@ -76,12 +76,14 @@ function findLogoFile() {
 router.get('/', async (req, res) => {
   try {
     const appName = await getSetting('app_name');
+    const defaultTheme = await getSetting('default_theme');
     const logoFile = findLogoFile();
 
     res.json({
       appName: appName || 'Redlight',
       hasLogo: !!logoFile,
       logoUrl: logoFile ? '/api/branding/logo' : null,
+      defaultTheme: defaultTheme || null,
     });
   } catch (err) {
     console.error('Get branding error:', err);
@@ -156,4 +158,19 @@ router.put('/name', authenticateToken, requireAdmin, async (req, res) => {
   }
 });
 
+// PUT /api/branding/default-theme - Set default theme for unauthenticated pages (admin only)
+router.put('/default-theme', authenticateToken, requireAdmin, async (req, res) => {
+  try {
+    const { defaultTheme } = req.body;
+    if (!defaultTheme || !defaultTheme.trim()) {
+      return res.status(400).json({ error: 'defaultTheme is required' });
+    }
+    await setSetting('default_theme', defaultTheme.trim());
+    res.json({ defaultTheme: defaultTheme.trim() });
+  } catch (err) {
+    console.error('Update default theme error:', err);
+    res.status(500).json({ error: 'Could not update default theme' });
+  }
+});
+
 export default router;