Fix language setting not being saved to database on admin settings page

- Added default_language field to general settings state in SettingsPage
- Replaced LanguageSelector component with simple select dropdown on settings page
- Fixed public settings endpoint to read general_default_language from database
- Language setting now properly saved when clicking Save Settings button
- Setting is correctly used by gallery login page and legal pages

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/src/routes/adminCMS.js

@@ -0,0 +1,83 @@
+const express = require('express');
+const { body, validationResult } = require('express-validator');
+const { db, logActivity } = require('../database/db');
+const { adminAuth } = require('../middleware/auth');
+const router = express.Router();
+
+// Get all CMS pages
+router.get('/pages', adminAuth, async (req, res) => {
+  try {
+    const pages = await db('cms_pages').select('*').orderBy('slug', 'asc');
+    res.json(pages);
+  } catch (error) {
+    console.error('Error fetching CMS pages:', error);
+    res.status(500).json({ error: 'Failed to fetch pages' });
+  }
+});
+
+// Get a single CMS page
+router.get('/pages/:slug', adminAuth, async (req, res) => {
+  try {
+    const { slug } = req.params;
+    const page = await db('cms_pages').where('slug', slug).first();
+    
+    if (!page) {
+      return res.status(404).json({ error: 'Page not found' });
+    }
+    
+    res.json(page);
+  } catch (error) {
+    console.error('Error fetching CMS page:', error);
+    res.status(500).json({ error: 'Failed to fetch page' });
+  }
+});
+
+// Update a CMS page
+router.put('/pages/:slug', adminAuth, [
+  body('title_en').optional().isString(),
+  body('title_de').optional().isString(),
+  body('content_en').optional().isString(),
+  body('content_de').optional().isString()
+], async (req, res) => {
+  try {
+    const errors = validationResult(req);
+    if (!errors.isEmpty()) {
+      return res.status(400).json({ errors: errors.array() });
+    }
+    
+    const { slug } = req.params;
+    const { title_en, title_de, content_en, content_de } = req.body;
+    
+    const page = await db('cms_pages').where('slug', slug).first();
+    if (!page) {
+      return res.status(404).json({ error: 'Page not found' });
+    }
+    
+    // Update the page
+    await db('cms_pages')
+      .where('slug', slug)
+      .update({
+        title_en,
+        title_de,
+        content_en,
+        content_de,
+        updated_at: new Date()
+      });
+    
+    const updated = await db('cms_pages').where('slug', slug).first();
+    
+    // Log activity
+    await logActivity('cms_page_updated',
+      { page: slug },
+      null,
+      { type: 'admin', id: req.admin.id, name: req.admin.username }
+    );
+    
+    res.json(updated);
+  } catch (error) {
+    console.error('Error updating CMS page:', error);
+    res.status(500).json({ error: 'Failed to update page' });
+  }
+});
+
+module.exports = router;