feat(settings): add settings page with server, watchdog and notification config

- Add new Settings view with form controls for server, watchdog and notification settings
- Implement API endpoints for getting and saving settings
- Add settings route and sidebar navigation item
- Update button styles to include text color variable
- Change default app target to local development address

src/components/SideBar.vue

@@ -54,7 +54,8 @@ export default {
             { path: '/sessions', title: 'Session Management', icon: 'fas fa-key', permission: ['superuser', 'admin'] },
             { path: '/logs', title: 'System Logs', icon: 'fas fa-file-alt', permission: ['superuser', 'admin'] },
             { path: '/monitor', title: 'System Monitoring', icon: 'fas fa-chart-bar', permission: ['superuser', 'admin', 'visitor'] },
-            { path: '/system-info', title: 'System Information', icon: 'fas fa-info-circle', permission: ['superuser', 'admin', 'visitor'] }
+            { path: '/system-info', title: 'System Information', icon: 'fas fa-info-circle', permission: ['superuser', 'admin', 'visitor'] },
+            { path: '/settings', title: 'Settings', icon: 'fas fa-cog', permission: ['superuser', 'admin'] }
         ];
 
         const menuItems = computed(() => {