refactor(backend): move every route to its own module

server/src/modules/notification-preferences/notification-preferences.routes.js

@@ -0,0 +1,30 @@
+import express from 'express';
+import { notificationPreferencesDb } from '../../../database/db.js';
+
+const router = express.Router();
+
+// ===============================
+// Notification Preferences
+// ===============================
+
+router.get('/', async (req, res) => {
+  try {
+    const preferences = notificationPreferencesDb.getPreferences(req.user.id);
+    res.json({ success: true, preferences });
+  } catch (error) {
+    console.error('Error fetching notification preferences:', error);
+    res.status(500).json({ error: 'Failed to fetch notification preferences' });
+  }
+});
+
+router.put('/', async (req, res) => {
+  try {
+    const preferences = notificationPreferencesDb.updatePreferences(req.user.id, req.body || {});
+    res.json({ success: true, preferences });
+  } catch (error) {
+    console.error('Error saving notification preferences:', error);
+    res.status(500).json({ error: 'Failed to save notification preferences' });
+  }
+});
+
+export default router;