Fix general settings route and req.user references

- Update frontend settings service to use correct /api/admin/settings/general route
- Fix all req.user to req.admin references in adminSettings.js
- Ensures settings can be saved without authentication errors

backend/src/routes/adminSettings.js

@@ -118,8 +118,8 @@ router.put('/branding', adminAuth, async (req, res) => {
     await db('activity_logs').insert({
       activity_type: 'branding_updated',
       actor_type: 'admin',
-      actor_id: req.user.id,
-      actor_name: req.user.username,
+      actor_id: req.admin.id,
+      actor_name: req.admin.username,
       metadata: JSON.stringify({ company_name })
     });
 
@@ -215,8 +215,8 @@ router.put('/theme', adminAuth, async (req, res) => {
     await db('activity_logs').insert({
       activity_type: 'theme_updated',
       actor_type: 'admin',
-      actor_id: req.user.id,
-      actor_name: req.user.username,
+      actor_id: req.admin.id,
+      actor_name: req.admin.username,
       metadata: JSON.stringify({ theme_name: themeSettings.name || 'custom' })
     });
 
@@ -252,8 +252,8 @@ router.put('/general', adminAuth, async (req, res) => {
     await db('activity_logs').insert({
       activity_type: 'general_settings_updated',
       actor_type: 'admin',
-      actor_id: req.user.id,
-      actor_name: req.user.username,
+      actor_id: req.admin.id,
+      actor_name: req.admin.username,
       metadata: JSON.stringify({ settings_count: Object.keys(settings).length })
     });
 
@@ -289,8 +289,8 @@ router.put('/security', adminAuth, async (req, res) => {
     await db('activity_logs').insert({
       activity_type: 'security_settings_updated',
       actor_type: 'admin',
-      actor_id: req.user.id,
-      actor_name: req.user.username,
+      actor_id: req.admin.id,
+      actor_name: req.admin.username,
       metadata: JSON.stringify({ settings_count: Object.keys(settings).length })
     });