fix(ui): unify scroll and improve playback switching

lib/pantallas/pantalla_buscar.dart

@@ -67,7 +67,8 @@ class _PantallaBuscarState extends State<PantallaBuscar> {
     final estado = context.watch<EstadoRadio>();
     final theme = Theme.of(context);
 
-    return Column(
+    return ListView(
+      padding: const EdgeInsets.fromLTRB(0, 0, 0, 124),
       children: [
         PluriScreenHeader(
           title: 'Buscar senal',
@@ -125,7 +126,7 @@ class _PantallaBuscarState extends State<PantallaBuscar> {
             _buscar();
           },
         ),
-        Expanded(child: _resultados(estado, theme)),
+        _resultados(estado, theme),
       ],
     );
   }
@@ -144,7 +145,7 @@ class _PantallaBuscarState extends State<PantallaBuscar> {
               children: [
                 Expanded(
                   child: Text(
-                    pais == null ? 'Emisoras cercanas' : 'Emisoras cercanas ? $pais',
+                    pais == null ? 'Emisoras cercanas' : 'Emisoras cercanas - $pais',
                     style: theme.textTheme.labelLarge?.copyWith(
                       fontWeight: FontWeight.w900,
                     ),
@@ -247,7 +248,10 @@ class _PantallaBuscarState extends State<PantallaBuscar> {
 
   Widget _resultados(EstadoRadio estado, ThemeData theme) {
     if (estado.cargandoBusqueda) {
-      return const Center(child: CircularProgressIndicator());
+      return const SizedBox(
+        height: 220,
+        child: Center(child: CircularProgressIndicator()),
+      );
     }
 
     final resultados = estado.resultadosBusqueda;
@@ -257,18 +261,24 @@ class _PantallaBuscarState extends State<PantallaBuscar> {
           _controller.text.isEmpty &&
           _paisSeleccionado == null &&
           _idiomaSeleccionado == null;
-      return PluriEmptyState(
-        glyph: PluriIconGlyph.search,
-        title: sinFiltros ? 'Busca una emisora' : 'Sin resultados',
-        subtitle: sinFiltros
-            ? 'Usa la barra superior o los chips para descubrir senales de todo el mundo.'
-            : 'Proba quitar filtros o escribir otro nombre para encontrar una senal activa.',
+      return SizedBox(
+        height: 260,
+        child: PluriEmptyState(
+          glyph: PluriIconGlyph.search,
+          title: sinFiltros ? 'Busca una emisora' : 'Sin resultados',
+          subtitle: sinFiltros
+              ? 'Usa la barra superior o los chips para descubrir senales de todo el mundo.'
+              : 'Proba quitar filtros o escribir otro nombre para encontrar una senal activa.',
+        ),
       );
     }
 
+    final total = resultados.length + (estado.hayMasBusqueda ? 1 : 0);
     return ListView.separated(
-      padding: const EdgeInsets.fromLTRB(16, 16, 16, 120),
-      itemCount: resultados.length + (estado.hayMasBusqueda ? 1 : 0),
+      shrinkWrap: true,
+      physics: const NeverScrollableScrollPhysics(),
+      padding: const EdgeInsets.fromLTRB(16, 16, 16, 16),
+      itemCount: total,
       separatorBuilder: (_, __) => const SizedBox(height: 10),
       itemBuilder: (context, i) {
         if (i >= resultados.length) {

lib/pantallas/pantalla_favoritos.dart

@@ -18,7 +18,8 @@ class PantallaFavoritos extends StatelessWidget {
     final favoritos = estado.listaFavoritos;
 
     if (favoritos.isEmpty) {
-      return const Column(
+      return ListView(
+        padding: EdgeInsets.fromLTRB(0, 0, 0, 124),
         children: [
           PluriScreenHeader(
             title: 'Favoritos',
@@ -29,7 +30,8 @@ class PantallaFavoritos extends StatelessWidget {
               label: 'Coleccion',
             ),
           ),
-          Expanded(
+          SizedBox(
+            height: 320,
             child: PluriEmptyState(
               glyph: PluriIconGlyph.favorites,
               title: 'Sin favoritos aun',
@@ -40,20 +42,22 @@ class PantallaFavoritos extends StatelessWidget {
       );
     }
 
-    return Column(
-      children: [
-        PluriScreenHeader(
-          title: 'Favoritos',
-          subtitle: 'Reordena tu coleccion y deja arriba las radios que mas importan.',
-          glyph: PluriIconGlyph.favorites,
-          trailing: PluriStatusPill(
-            icon: Icons.library_music_rounded,
-            label: '${favoritos.length} guardadas',
+    return CustomScrollView(
+      slivers: [
+        SliverToBoxAdapter(
+          child: PluriScreenHeader(
+            title: 'Favoritos',
+            subtitle: 'Reordena tu coleccion y deja arriba las radios que mas importan.',
+            glyph: PluriIconGlyph.favorites,
+            trailing: PluriStatusPill(
+              icon: Icons.library_music_rounded,
+              label: '${favoritos.length} guardadas',
+            ),
           ),
         ),
-        Expanded(
-          child: ReorderableListView.builder(
-            padding: const EdgeInsets.fromLTRB(12, 4, 12, 122),
+        SliverPadding(
+          padding: const EdgeInsets.fromLTRB(12, 4, 12, 124),
+          sliver: SliverReorderableList(
             proxyDecorator: (child, index, animation) => ScaleTransition(
               scale: Tween<double>(begin: 1, end: 1.03).animate(animation),
               child: child,

lib/pantallas/pantalla_inicio.dart

@@ -48,7 +48,6 @@ class _PantallaInicioState extends State<PantallaInicio> {
       child: CustomScrollView(
         slivers: [
           SliverToBoxAdapter(child: _heroHeader(context, estado)),
-          const SliverToBoxAdapter(child: _AuroraWaveBanner()),
           SliverToBoxAdapter(child: _seccionCercanas(estado, theme)),
           SliverToBoxAdapter(child: _seccionTendencias(estado, theme)),
           SliverToBoxAdapter(child: _chipGeneros(context, theme)),
@@ -312,64 +311,6 @@ class _PantallaInicioState extends State<PantallaInicio> {
 }
 
 
-class _AuroraWaveBanner extends StatelessWidget {
-  const _AuroraWaveBanner();
-
-  @override
-  Widget build(BuildContext context) {
-    final t = context.pluriTokens;
-    return Padding(
-      padding: EdgeInsets.fromLTRB(t.spacingMd, 4, t.spacingMd, 8),
-      child: ClipRRect(
-        borderRadius: BorderRadius.circular(t.radiusLg),
-        child: Stack(
-          alignment: Alignment.centerLeft,
-          children: [
-            Image.asset(
-              'assets/images/aurora_wave_banner.png',
-              height: 108,
-              width: double.infinity,
-              fit: BoxFit.cover,
-              errorBuilder: (_, __, ___) => const SizedBox.shrink(),
-            ),
-            Container(
-              height: 108,
-              decoration: BoxDecoration(
-                gradient: LinearGradient(
-                  colors: [
-                    Colors.black.withValues(alpha: 0.58),
-                    Colors.transparent,
-                  ],
-                ),
-              ),
-            ),
-            Padding(
-              padding: const EdgeInsets.all(16),
-              child: Column(
-                crossAxisAlignment: CrossAxisAlignment.start,
-                mainAxisSize: MainAxisSize.min,
-                children: [
-                  Text(
-                    'Live spectrum',
-                    style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                          fontWeight: FontWeight.w900,
-                        ),
-                  ),
-                  const SizedBox(height: 4),
-                  Text(
-                    'Ondas aurora en tiempo real',
-                    style: Theme.of(context).textTheme.bodySmall,
-                  ),
-                ],
-              ),
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-}
-
 class _ChipShimmer extends StatelessWidget {
   final ThemeData theme;
   const _ChipShimmer({required this.theme});

lib/servicios/servicio_audio.dart

@@ -106,7 +106,7 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
 
   PresetEcualizador _presetActual = PresetEcualizador.flat;
   PresetEcualizador get presetActual => _presetActual;
-  Future<void> _colaReproduccion = Future<void>.value();
+  int _playRequestId = 0;
 
   PluriWaveAudioHandler() {
     _setupStreams();
@@ -214,14 +214,8 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
   }
 
   @override
-  Future<void> playMediaItem(MediaItem mediaItem) {
-    _colaReproduccion = _colaReproduccion
-        .catchError((_) {})
-        .then((_) => _playMediaItemSerializado(mediaItem));
-    return _colaReproduccion;
-  }
-
-  Future<void> _playMediaItemSerializado(MediaItem mediaItem) async {
+  Future<void> playMediaItem(MediaItem mediaItem) async {
+    final requestId = ++_playRequestId;
     this.mediaItem.add(mediaItem);
     emisoraActual = _emisoraDesdeMediaItem(mediaItem);
     playbackState.add(playbackState.value.copyWith(
@@ -231,11 +225,17 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
     ));
     try {
       await _player.stop();
+      if (requestId != _playRequestId) return;
       await _player.setUrl(mediaItem.id);
+      if (requestId != _playRequestId) return;
       await _player.play();
-      await _activarEcualizador();
+      if (requestId == _playRequestId) {
+        await _activarEcualizador();
+      }
     } on PlayerException catch (e) {
-      _gestionarErrorReproduccion(e);
+      if (requestId == _playRequestId) {
+        _gestionarErrorReproduccion(e);
+      }
       throw Exception(_mensajeAmigable(e));
     } on Exception catch (e) {
       developer.log(
@@ -243,13 +243,15 @@ class PluriWaveAudioHandler extends BaseAudioHandler with SeekHandler {
         name: 'ServicioAudio',
         level: 900,
       );
-      playbackState.add(playbackState.value.copyWith(
-        processingState: AudioProcessingState.error,
-        playing: false,
-        errorMessage: 'Error inesperado al reproducir',
-      ));
-      emisoraActual = null;
-      this.mediaItem.add(null);
+      if (requestId == _playRequestId) {
+        playbackState.add(playbackState.value.copyWith(
+          processingState: AudioProcessingState.error,
+          playing: false,
+          errorMessage: 'Error inesperado al reproducir',
+        ));
+        emisoraActual = null;
+        this.mediaItem.add(null);
+      }
       rethrow;
     }
   }

lib/widgets/visualizador_audio.dart

@@ -45,31 +45,20 @@ class VisualizadorAudio extends StatefulWidget {
 }
 
 class _VisualizadorAudioState extends State<VisualizadorAudio>
-    with TickerProviderStateMixin {
+    with SingleTickerProviderStateMixin {
   late AnimationController _controller;
-  late List<_BarraState> _barras;
-  final _random = Random();
   bool _activo = false;
   StreamSubscription<EstadoReproduccion>? _estadoSubscription;
 
   @override
   void initState() {
     super.initState();
-    _barras = List.generate(
-      widget.barras,
-      (i) => _BarraState(
-        fase: _random.nextDouble() * pi * 2,
-        velocidad: 0.8 + _random.nextDouble() * 1.4,
-        amplitud: 0.4 + _random.nextDouble() * 0.6,
-        offset: _random.nextDouble() * 0.3,
-      ),
-    );
-
     _controller = AnimationController(
       vsync: this,
-      duration: const Duration(seconds: 1),
-    )..addListener(_actualizar);
-
+      duration: const Duration(seconds: 2),
+    )..addListener(() {
+        if (mounted) setState(() {});
+      });
     _estadoSubscription = widget.estadoStream.listen(_onEstado);
   }
 
@@ -79,17 +68,7 @@ class _VisualizadorAudioState extends State<VisualizadorAudio>
     if (nuevoActivo == _activo) return;
     if (!mounted) return;
     setState(() => _activo = nuevoActivo);
-    if (nuevoActivo) {
-      _controller.repeat();
-    } else {
-      _controller.forward(from: _controller.value).whenComplete(() {
-        if (!_activo && mounted) _controller.stop();
-      });
-    }
-  }
-
-  void _actualizar() {
-    if (mounted) setState(() {});
+    nuevoActivo ? _controller.repeat() : _controller.stop();
   }
 
   @override
@@ -103,75 +82,86 @@ class _VisualizadorAudioState extends State<VisualizadorAudio>
   Widget build(BuildContext context) {
     final color = widget.color ?? Theme.of(context).colorScheme.primary;
     final t = _controller.value * pi * 2;
-
     return SizedBox(
       height: widget.altura,
-      child: LayoutBuilder(
-        builder: (context, constraints) {
-          final totalAncho = constraints.maxWidth == double.infinity
-              ? 300.0
-              : constraints.maxWidth;
-          final espaciado = totalAncho / widget.barras;
-          final anchoBar = (espaciado * 0.55).clamp(2.0, 8.0);
-
-          return RepaintBoundary(
-            child: Row(
-              mainAxisAlignment: MainAxisAlignment.center,
-              crossAxisAlignment: CrossAxisAlignment.end,
-              children: List.generate(widget.barras, (i) {
-              final b = _barras[i];
-              final double altura;
-
-              if (_activo) {
-                // Movimiento orgánico: combinación de senos con diferentes fases
-                final onda1 = sin(t * b.velocidad + b.fase);
-                final onda2 = sin(t * b.velocidad * 0.7 + b.fase * 1.3) * 0.5;
-                final valor = ((onda1 + onda2 + 1.5) / 3.0).clamp(0.0, 1.0);
-                altura = (b.offset + valor * b.amplitud) * widget.altura;
-              } else {
-                // Decaer suavemente a altura mínima
-                final progreso = _controller.value;
-                final alturaActual = b.alturaActual;
-                b.alturaActual = alturaActual * (1 - progreso * 0.1);
-                altura = b.alturaActual.clamp(2.0, widget.altura * 0.05);
-              }
-
-                return Padding(
-                  padding: EdgeInsets.symmetric(horizontal: (espaciado - anchoBar) / 2),
-                  child: AnimatedContainer(
-                    duration: const Duration(milliseconds: 80),
-                    width: anchoBar,
-                    height: altura.clamp(2.0, widget.altura),
-                    decoration: BoxDecoration(
-                      color: color.withValues(
-                        alpha: _activo ? 0.7 + (altura / widget.altura) * 0.3 : 0.3,
-                      ),
-                      borderRadius: BorderRadius.circular(anchoBar / 2),
-                    ),
-                  ),
-                );
-              }),
-            ),
-          );
-        },
+      child: RepaintBoundary(
+        child: CustomPaint(
+          painter: _WaveFlowPainter(
+            color: color,
+            phase: t,
+            active: _activo,
+          ),
+          child: const SizedBox.expand(),
+        ),
       ),
     );
   }
 }
 
-class _BarraState {
-  final double fase;
-  final double velocidad;
-  final double amplitud;
-  final double offset;
-  double alturaActual;
+class _WaveFlowPainter extends CustomPainter {
+  const _WaveFlowPainter({
+    required this.color,
+    required this.phase,
+    required this.active,
+  });
 
-  _BarraState({
-    required this.fase,
-    required this.velocidad,
-    required this.amplitud,
-    required this.offset,
-  }) : alturaActual = offset * 20;
+  final Color color;
+  final double phase;
+  final bool active;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final center = size.height / 2;
+    final amp = active ? size.height * 0.24 : size.height * 0.06;
+    final glowPaint = Paint()
+      ..style = PaintingStyle.stroke
+      ..strokeWidth = active ? 8 : 4
+      ..strokeCap = StrokeCap.round
+      ..color = color.withValues(alpha: active ? 0.18 : 0.08);
+    final linePaint = Paint()
+      ..style = PaintingStyle.stroke
+      ..strokeWidth = 3
+      ..strokeCap = StrokeCap.round
+      ..shader = LinearGradient(
+        colors: [
+          color.withValues(alpha: 0.08),
+          color.withValues(alpha: active ? 0.95 : 0.35),
+          const Color(0xFFF4B860).withValues(alpha: active ? 0.75 : 0.20),
+          color.withValues(alpha: 0.08),
+        ],
+      ).createShader(Offset.zero & size);
+
+    Path pathFor(double shift, double amplitude) {
+      final path = Path()..moveTo(0, center);
+      for (double x = 0; x <= size.width; x += 8) {
+        final p = x / size.width;
+        final y = center +
+            sin((p * pi * 2.4) + phase + shift) * amplitude +
+            sin((p * pi * 5.2) - phase * 0.7 + shift) * amplitude * 0.32;
+        path.lineTo(x, y);
+      }
+      return path;
+    }
+
+    canvas.drawPath(pathFor(0, amp), glowPaint);
+    canvas.drawPath(pathFor(0.6, amp * 0.62), glowPaint..color = color.withValues(alpha: active ? 0.10 : 0.05));
+    canvas.drawPath(pathFor(0, amp), linePaint);
+    canvas.drawPath(
+      pathFor(0.9, amp * 0.58),
+      Paint()
+        ..style = PaintingStyle.stroke
+        ..strokeWidth = 2
+        ..strokeCap = StrokeCap.round
+        ..color = Colors.white.withValues(alpha: active ? 0.35 : 0.12),
+    );
+  }
+
+  @override
+  bool shouldRepaint(covariant _WaveFlowPainter oldDelegate) {
+    return oldDelegate.phase != phase ||
+        oldDelegate.active != active ||
+        oldDelegate.color != color;
+  }
 }
 
 /// Versión compacta del visualizador — 5 barras, para uso en MiniReproductor