feat(tutorial): repoint Ajustes "Ayuda y tutorial" to the carousel

Point the existing Info tile at PantallaTutorialAyuda (with
primerArranque: false, so its last page reads "Close") instead of
PluriOnboardingDialog's "what's new" modal.

Trade-off: PluriOnboardingDialog loses its only manual entry point --
it keeps auto-showing on its own existing cadence from app.dart, but
is no longer reachable by tapping this tile. This matches the mockup's
Info screen, which has no separate "what's new" row.

lib/pantallas/ajustes/pantalla_ajustes_info.dart

@@ -7,8 +7,8 @@ import '../../l10n/gen/app_localizations.dart';
 import '../../widgets/pluri_glass_surface.dart';
 import '../../widgets/pluri_icon.dart';
 import '../../widgets/pluri_layout.dart';
-import '../../widgets/pluri_onboarding_dialog.dart';
 import '../../widgets/pluri_push_scaffold.dart';
+import '../pantalla_tutorial_ayuda.dart';
 
 /// APLICACIÓN group · "Info" (design ADR-3). Body moved verbatim from the
 /// former `_SeccionInfo` in `pantalla_ajustes.dart`. Unlike the other four
@@ -86,7 +86,15 @@ class _CuerpoInfo extends StatelessWidget {
                   title: Text(AppLocalizations.of(ctx).helpTitle),
                   subtitle: Text(AppLocalizations.of(ctx).helpSubtitle),
                   trailing: const Icon(Icons.chevron_right_rounded),
-                  onTap: () => PluriOnboardingDialog.mostrar(ctx),
+                  onTap:
+                      () => Navigator.of(ctx).push(
+                        MaterialPageRoute<void>(
+                          builder:
+                              (_) => const PantallaTutorialAyuda(
+                                primerArranque: false,
+                              ),
+                        ),
+                      ),
                 ),
                 ListTile(
                   contentPadding: EdgeInsets.zero,