feat(settings): agregar opcion global para habilitar o deshabilitar saludo y selector de rol en dashboard

frontend/src/routes/admin.js

@@ -1406,6 +1406,9 @@ const handleGlobalSettings = async (req, res) => {
     if (settings && settings.moodle) {
         settings.moodle.ws_token_masked = settings.moodle.ws_token_masked || settings.moodle.ws_token || '';
     }
+    if (settings) {
+        settings.ui = settings.ui || { show_role_banner: true };
+    }
 
     try {
         const demoResp = await req.apiClient.get('/settings/demo-mode');
@@ -1503,5 +1506,6 @@ router.post('/settings/moodle', forwardSettingsAction);
 router.post('/settings/moodle/test', forwardSettingsAction);
 router.post('/settings/moodle/sync', forwardSettingsAction);
 router.get('/settings/moodle/stats', forwardSettingsAction);
+router.post('/settings/ui', forwardSettingsAction);
 
 module.exports = router;

frontend/src/routes/dashboard.js

@@ -266,6 +266,11 @@ router.get('/', async (req, res) => {
         { start_time: '18:30', end_time: '22:30', date_display: '24/09', subject_name: 'Ingeniería de Software', subject_code: 'IS-301', shift: 'Noche', commission: { code: 'COM-3' }, status: 'PENDING', classroom: { code: 'Aula Magna' }, user: { name: 'Ing. Marcos Ruiz' } }
     ];
 
+    let show_role_banner = true;
+    if (apiData && apiData.ui && apiData.ui.show_role_banner !== undefined) {
+        show_role_banner = Boolean(apiData.ui.show_role_banner);
+    }
+
     res.render('dashboard', {
         title: role === 'bedelia' ? 'Panel Operativo de Bedelía - Edu-Space Admin' :
                role === 'docente' ? 'Panel Docente - Edu-Space Admin' :
@@ -274,6 +279,7 @@ router.get('/', async (req, res) => {
         user: req.user,
         role,
         actual_role,
+        show_role_banner,
         stats,
         role_data,
         monthly_data,