fix(escuchar): show the station meta line in the hero

Audit 1.6 (t4 line 62): the Escuchar hero never rendered "genre ·
country · bitrate kbps" between the station name and the visualizer.
Built from fields Emisora already carries (tags/pais/bitrate) — no
new fields, no service calls — omitting gracefully whatever a station
lacks.

lib/pantallas/pantalla_inicio.dart

@@ -267,6 +267,22 @@ class _EscucharHero extends StatelessWidget {
                         maxLines: 2,
                         overflow: TextOverflow.ellipsis,
                       ),
+                      if (_metaEscuchar(emisora) case final meta?) ...[
+                        const SizedBox(height: 4),
+                        Text(
+                          meta,
+                          key: const ValueKey('escuchar-hero-meta'),
+                          style: TextStyle(
+                            fontSize: 12.5,
+                            fontWeight: FontWeight.w600,
+                            color: theme.colorScheme.onSurface.withValues(
+                              alpha: 0.62,
+                            ),
+                          ),
+                          maxLines: 1,
+                          overflow: TextOverflow.ellipsis,
+                        ),
+                      ],
                       const SizedBox(height: 8),
                       VisualizadorAudio(
                         estadoStream: estado.estadoStream,
@@ -536,3 +552,17 @@ class _FilaTransporteEscuchar extends StatelessWidget {
         : l10n.durationMinutesSeconds(d.inMinutes, s);
   }
 }
+
+/// Audit 1.6 (t4 line 62): "género · país · kbps" built ONLY from fields
+/// [Emisora] already carries (`tags`/`pais`/`bitrate`) — no new fields, no
+/// service calls. Whatever a station lacks is omitted gracefully; this
+/// never renders a stray leading/trailing/doubled " · ".
+String? _metaEscuchar(Emisora emisora) {
+  final partes = <String>[
+    if (emisora.generos.isNotEmpty) emisora.generos.first,
+    if (emisora.pais != null && emisora.pais!.isNotEmpty) emisora.pais!,
+    if (emisora.bitrate != null && emisora.bitrate! > 0)
+      '${emisora.bitrate} kbps',
+  ];
+  return partes.isEmpty ? null : partes.join(' · ');
+}