fix(favoritos,grabaciones): replace glass cards with flat rows

Item 23 / audit 4.3, 12.4 (t4:226-232, 616-619): Favoritos and
Grabaciones rows were full glass cards / ListTiles with two stacked
buttons and no artwork slot. Replace with flat, background-less rows
via a new shared FilaEmisoraPlana widget (square art, name+meta, a
circular play affordance) plus a bespoke Grabaciones row (44x12
placeholder art -- recordings carry no per-station favicon, so this
is a themed fallback, not invented artwork).

Favoritos keeps "Move to list" / "Remove from favorites" behind an
overflow menu (same underlying methods, unchanged) instead of two
always-visible buttons, since dropping either would be a functional
regression the prototype's own row doesn't have to solve for.

Also 12.1 (t4:610): the Grabaciones header action is folder_open, not
a generic gear.

test/pantallas/pantalla_favoritos_test.dart

@@ -6,7 +6,9 @@ import 'package:pluriwave/estado/estado_radio.dart';
 import 'package:pluriwave/l10n/gen/app_localizations.dart';
 import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_grupos_favoritos.dart';
 import 'package:pluriwave/pantallas/pantalla_favoritos.dart';
+import 'package:pluriwave/widgets/fila_emisora_plana.dart';
 import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
+import 'package:pluriwave/widgets/tarjeta_emisora.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
@@ -381,6 +383,90 @@ void main() {
 
     expect(find.widgetWithText(TextFormField, 'Name *'), findsOneWidget);
   });
+
+  // Item 23 / audit 4.3 (t4:226-232): flat, background-less rows with a
+  // square thumbnail and a circular play affordance, replacing the full
+  // glass TarjetaEmisora card + two stacked filledTonal buttons.
+  group('Item 23 -- flat rows (audit 4.3)', () {
+    testWidgets(
+      'each row is a flat FilaEmisoraPlana, not the full glass card',
+      (tester) async {
+        setLargeSurface(tester);
+        _suppressListTileInkAssertion();
+        final estado = await crearEstadoConFavoritos();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await pumpStable(tester);
+
+        expect(find.byType(FilaEmisoraPlana), findsNWidgets(3));
+        expect(
+          find.byType(TarjetaEmisora),
+          findsNothing,
+          reason: 'audit 4.3 replaces the full glass card with a flat row',
+        );
+        expect(
+          find.byIcon(Icons.drag_indicator_rounded),
+          findsNWidgets(3),
+          reason: 't4:227 drag_indicator, not drag_handle',
+        );
+        expect(find.byIcon(Icons.drag_handle_rounded), findsNothing);
+        expect(
+          find.byType(BotonReproducirCircular),
+          findsNWidgets(3),
+          reason: 't4:230 a circular play affordance per row',
+        );
+      },
+    );
+
+    testWidgets(
+      'the overflow menu offers exactly "Move to list" and "Remove from '
+      'favorites"',
+      (tester) async {
+        setLargeSurface(tester);
+        _suppressListTileInkAssertion();
+        final estado = await crearEstadoConFavoritos();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await pumpStable(tester);
+
+        await tester.tap(find.byIcon(Icons.more_vert_rounded).first);
+        await tester.pumpAndSettle();
+
+        expect(find.text('Move to list'), findsOneWidget);
+        expect(find.text('Remove from favorites'), findsOneWidget);
+        expect(find.byType(PopupMenuItem<String>), findsNWidgets(2));
+      },
+    );
+
+    testWidgets(
+      '"Remove from favorites" still calls the same removal path as before',
+      (tester) async {
+        setLargeSurface(tester);
+        _suppressListTileInkAssertion();
+        final estado = await crearEstadoConFavoritos();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await pumpStable(tester);
+
+        // Invoke the callback directly rather than opening the overlay and
+        // tapping its rendered item by screen position: leaving that modal
+        // route open while the tap it triggers removes and unmounts the
+        // very row that anchors it is a real hang hazard, confirmed while
+        // developing this test (multi-minute stall, same class of risk as
+        // the project's other documented `pumpAndSettle` traps).
+        final boton = tester.widget<PopupMenuButton<String>>(
+          find.byType(PopupMenuButton<String>).first,
+        );
+        boton.onSelected!('remove');
+        await pumpStable(tester);
+
+        expect(find.text('Station A'), findsNothing);
+      },
+    );
+  });
 }
 
 void setLargeSurface(WidgetTester tester) {