fix(reproductor): move the quality row last and size the play button at 78

Audit 2.4 and 2.6: the quality row sat right after the subtitle, four
positions before where the prototype puts it (t4:114-140), and the play
button was 72 with a 40 icon instead of 78/42 (t4:127).

lib/pantallas/pantalla_reproductor.dart

@@ -145,11 +145,6 @@ class _PantallaReproductorState extends State<PantallaReproductor> {
               _SubtituloInfo(
                 emisora: emisoraActiva,
               ).pluriFadeIn(context, delay: const Duration(milliseconds: 190)),
-              const SizedBox(height: 12),
-              _FilaCalidad(
-                estado: estado,
-                emisora: emisoraActiva,
-              ).pluriFadeIn(context, delay: const Duration(milliseconds: 230)),
               const SizedBox(height: 14),
               PluriGlassSurface(
                 key: const Key('player-visualizer'),
@@ -188,6 +183,14 @@ class _PantallaReproductorState extends State<PantallaReproductor> {
                 emisora: emisoraActiva,
                 compartir: _compartir,
               ).pluriFadeIn(context, delay: const Duration(milliseconds: 350)),
+              const SizedBox(height: 12),
+              // Item 26 / audit 2.4 (t4:114-140): the quality row is LAST,
+              // after the tool tray -- it used to sit right after the
+              // subtitle, 4 positions too early.
+              _FilaCalidad(
+                estado: estado,
+                emisora: emisoraActiva,
+              ).pluriFadeIn(context, delay: const Duration(milliseconds: 390)),
             ],
           ),
         ),
@@ -799,8 +802,9 @@ class _Controles extends StatelessWidget {
               ),
               AnimatedContainer(
                 duration: const Duration(milliseconds: 200),
-                width: 72,
-                height: 72,
+                // Item 26 / audit 2.6 (t4:127): 78x78, not 72x72.
+                width: 78,
+                height: 78,
                 decoration: BoxDecoration(
                   shape: BoxShape.circle,
                   color: theme.colorScheme.primary,
@@ -817,7 +821,7 @@ class _Controles extends StatelessWidget {
                   shape: const CircleBorder(),
                   child: InkWell(
                     customBorder: const CircleBorder(),
-                    radius: 40,
+                    radius: 39,
                     onTap:
                         cargando
                             ? null
@@ -850,7 +854,8 @@ class _Controles extends StatelessWidget {
                                   reproduciendo
                                       ? Icons.pause_rounded
                                       : Icons.play_arrow_rounded,
-                                  size: 40,
+                                  // Item 26 / audit 2.6 (t4:127): 42px icon.
+                                  size: 42,
                                   color: theme.colorScheme.onPrimary,
                                 ),
                       ),