fix(eq): restore the prototype's band height and brand-teal fill

Audit 11.4 and 11.6: the band column was 152 instead of 280 (t4 line
581), leaving the sliders 46% short, and the fill read liveGreen -- the
LIVE badge colour -- instead of brand teal (t4 line 585).

Adds two guards. The existing tests only asserted the band COUNT, which
is exactly why both values could drift unnoticed.

lib/widgets/ecualizador_widget.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 import '../l10n/gen/app_localizations.dart';
 import '../modelos/preset_ecualizador.dart';
 import '../tema/pluriwave_theme.dart';
+import '../tema/pluriwave_tokens.dart';
 import 'pluri_glass_surface.dart';
 
 class EcualizadorWidget extends StatefulWidget {
@@ -87,7 +88,9 @@ class _EcualizadorWidgetState extends State<EcualizadorWidget> {
                     child: Column(
                       children: [
                         SizedBox(
-                          height: 152,
+                          // Audit 11.4: the prototype draws the band column at
+                          // 280 (t4 line 581); 152 left the sliders 46% short.
+                          height: 280,
                           child: Semantics(
                             slider: true,
                             enabled: widget.habilitado,
@@ -100,13 +103,16 @@ class _EcualizadorWidgetState extends State<EcualizadorWidget> {
                               child: SliderTheme(
                                 data: SliderTheme.of(context).copyWith(
                                   trackHeight: 5,
-                                  activeTrackColor: tokens.liveGreen,
-                                  thumbColor: tokens.liveGreen,
+                                  // Audit 11.6: the prototype's band fill is
+                                  // brand teal (t4 line 585). `liveGreen` is
+                                  // the LIVE badge colour and reading it here
+                                  // put the sliders in the wrong colour family.
+                                  activeTrackColor: PluriWaveTokens.brand,
+                                  thumbColor: PluriWaveTokens.brand,
                                   inactiveTrackColor:
                                       theme.colorScheme.surfaceContainerHighest,
-                                  overlayColor: tokens.liveGreen.withValues(
-                                    alpha: 0.15,
-                                  ),
+                                  overlayColor: PluriWaveTokens.brand
+                                      .withValues(alpha: 0.15),
                                 ),
                                 child: Slider(
                                   value: _bandas[i],