fix: require city and phone (not just name) before switching to pro mode

Aligns the profile-completeness gate in the sidebar with the mobile app,
and reports which specific field is missing instead of a generic message.

lib/ui/shared/sidebar.dart

@@ -179,9 +179,20 @@ class Sidebar extends StatelessWidget {
               cursor: SystemMouseCursors.click,
               child: GestureDetector(
                 onTap: () {
-                  if (authProvider.user?.name == null ||
-                      authProvider.user?.name == '') {
-                    NotificationsService.showSnackBarError('Primero completa tu perfil');
+                  final missing = <String>[
+                    if (authProvider.user?.name == null ||
+                        authProvider.user?.name == '')
+                      'nombre',
+                    if (authProvider.user?.city == null ||
+                        authProvider.user?.city == '')
+                      'ciudad',
+                    if (authProvider.user?.phone == null ||
+                        authProvider.user?.phone == '')
+                      'teléfono',
+                  ];
+                  if (missing.isNotEmpty) {
+                    NotificationsService.showSnackBarError(
+                        'Completa tu perfil: falta ${missing.join(', ')}');
                     navigateTo(Flurorouter.profileRoute);
                     return;
                   }