feat(buscar): add discovery landing state, filter pills, counter, and sort

test/pantallas/pantalla_buscar_shimmer_test.dart

@@ -1,15 +1,26 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:pluriwave/estado/estado_busqueda.dart';
+import 'package:pluriwave/estado/estado_ecualizador.dart';
+import 'package:pluriwave/estado/estado_grabacion.dart';
+import 'package:pluriwave/estado/estado_radio.dart';
 import 'package:pluriwave/l10n/gen/app_localizations.dart';
 import 'package:pluriwave/pantallas/pantalla_buscar.dart';
 import 'package:pluriwave/widgets/tarjeta_emisora.dart';
 import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 import '../helpers/fakes.dart';
 
 /// S5-R6: the search loading state uses shimmer placeholders, not a bare
 /// spinner, to stay consistent with the rest of the app.
+///
+/// WU6 correction: `PantallaBuscar` now also renders a discovery LANDING
+/// state (task 6.5) that reads `EstadoRadio` directly, so any widget test
+/// mounting it — this one included — must provide a full `EstadoRadio`
+/// provider from the start, not just `EstadoBusqueda`. A non-empty query is
+/// entered first so the screen leaves the landing state and reaches the
+/// search-results branch this test actually targets.
 class _BusquedaCargando extends EstadoBusqueda {
   _BusquedaCargando() : super(radio: FakeServicioRadio());
 
@@ -18,13 +29,36 @@ class _BusquedaCargando extends EstadoBusqueda {
 }
 
 void main() {
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
   testWidgets('PantallaBuscar muestra shimmer mientras carga', (tester) async {
     final busqueda = _BusquedaCargando();
     addTearDown(busqueda.dispose);
+    final estado = EstadoRadio(
+      audio: FakeServicioAudio(),
+      favoritos: FakeServicioFavoritos(),
+      radio: FakeServicioRadio(),
+      servicioEcualizador: FakeServicioEcualizador(),
+      servicioGrabacion: FakeServicioGrabacionRadio(),
+      resolverArchivoCustom: () async => throw UnimplementedError(),
+      iniciarAutomaticamente: false,
+    );
+    addTearDown(estado.dispose);
 
     await tester.pumpWidget(
-      ListenableProvider<EstadoBusqueda>.value(
-        value: busqueda,
+      MultiProvider(
+        providers: [
+          ChangeNotifierProvider<EstadoRadio>.value(value: estado),
+          ListenableProvider<EstadoEcualizador>.value(
+            value: estado.ecualizador,
+          ),
+          ListenableProvider<EstadoGrabacion>.value(value: estado.grabacion),
+          // Overrides EstadoRadio's own (unused here) EstadoBusqueda with a
+          // fake pinned to cargando: true.
+          ListenableProvider<EstadoBusqueda>.value(value: busqueda),
+        ],
         child: MaterialApp(
           locale: const Locale('es'),
           localizationsDelegates: AppLocalizations.localizationsDelegates,
@@ -35,6 +69,12 @@ void main() {
     );
     await tester.pump();
 
+    // Still the landing state — no query entered yet.
+    expect(find.byType(TarjetaEmisoraShimmer), findsNothing);
+
+    await tester.enterText(find.byType(SearchBar), 'jazz');
+    await tester.pump();
+
     expect(find.byType(TarjetaEmisoraShimmer), findsWidgets);
     expect(find.byType(CircularProgressIndicator), findsNothing);
   });