feat(iap): wire real AdMob app id, banner and interstitial units

App id always uses the real value (SDK init only, no ad-serving risk).
Banner/interstitial pick the real unit id in release builds and Google's
test unit id everywhere else, so debug/profile builds can never serve
(or accidentally tap) a real ad.

lib/widgets/banner_anuncio_superior.dart

@@ -40,7 +40,7 @@ class _BannerAnuncioSuperiorState extends State<BannerAnuncioSuperior> {
     // load failure takes in production. Never throws out of this method.
     final anuncio = BannerAd(
       size: AdSize.banner,
-      adUnitId: bannerAdUnitIdPrueba,
+      adUnitId: bannerAdUnitId,
       request: const AdRequest(),
       listener: BannerAdListener(
         onAdLoaded: (ad) {