Revert "Layer voice wave under grid"

This reverts commit 8fda6f554d.

lib/screens/mapflow_shell.dart

@@ -1359,31 +1359,17 @@ class _VoiceInformationField extends StatelessWidget {
         ),
         LayoutBuilder(
           builder: (context, constraints) {
-            final paintSize = Size(
-              constraints.maxWidth,
-              constraints.maxHeight.clamp(300.0, 520.0),
-            );
-            return Stack(
-              alignment: Alignment.center,
-              children: [
-                CustomPaint(
-                  size: paintSize,
-                  painter: _VoiceWaveUnderlayPainter(
-                    samples: samples,
-                    active: active,
-                    liveLevel: liveLevel,
-                  ),
-                ),
-                CustomPaint(
-                  size: paintSize,
-                  painter: _VoiceInformationPainter(
-                    samples: samples,
-                    active: active,
-                    progress: progress,
-                    liveLevel: liveLevel,
-                  ),
-                ),
-              ],
+            return CustomPaint(
+              size: Size(
+                constraints.maxWidth,
+                constraints.maxHeight.clamp(300.0, 520.0),
+              ),
+              painter: _VoiceInformationPainter(
+                samples: samples,
+                active: active,
+                progress: progress,
+                liveLevel: liveLevel,
+              ),
             );
           },
         ),
@@ -1392,92 +1378,6 @@ class _VoiceInformationField extends StatelessWidget {
   }
 }
 
-class _VoiceWaveUnderlayPainter extends CustomPainter {
-  const _VoiceWaveUnderlayPainter({
-    required this.samples,
-    required this.active,
-    required this.liveLevel,
-  });
-
-  final List<double> samples;
-  final bool active;
-  final double liveLevel;
-
-  @override
-  void paint(Canvas canvas, Size size) {
-    if (samples.isEmpty) {
-      return;
-    }
-
-    final centerY = size.height * 0.52;
-    final width = math.min(size.width, 420.0);
-    final startX = (size.width - width) / 2;
-    final endX = startX + width;
-    final visibleSamples = samples.length.clamp(24, 96);
-    final sampleStart = math.max(0, samples.length - visibleSamples);
-    final baseline = 12.0 + liveLevel * 34.0;
-    final topPath = Path();
-    final bottomPath = Path();
-
-    for (var index = 0; index < visibleSamples; index++) {
-      final sample = samples[sampleStart + index].clamp(0.0, 1.0);
-      final x = startX + width * (index / math.max(1, visibleSamples - 1));
-      final phase = index * 0.52;
-      final lift = baseline + sample * 112.0;
-      final softWave = math.sin(phase) * (8.0 + liveLevel * 14.0);
-      final y = centerY - lift * 0.5 + softWave;
-      final mirrorY = centerY + lift * 0.5 - softWave;
-      if (index == 0) {
-        topPath.moveTo(x, y);
-        bottomPath.moveTo(x, mirrorY);
-      } else {
-        topPath.lineTo(x, y);
-        bottomPath.lineTo(x, mirrorY);
-      }
-    }
-
-    final fillPath = Path.from(topPath)
-      ..lineTo(endX, centerY)
-      ..lineTo(endX, centerY)
-      ..addPath(bottomPath, Offset.zero)
-      ..lineTo(startX, centerY)
-      ..close();
-    final alpha = active ? 0.10 + liveLevel * 0.16 : 0.05;
-    final fillPaint = Paint()
-      ..shader = LinearGradient(
-        begin: Alignment.centerLeft,
-        end: Alignment.centerRight,
-        colors: [
-          const Color(0xFF38F5D3).withValues(alpha: alpha * 0.35),
-          const Color(0xFFFF2D75).withValues(alpha: alpha),
-          const Color(0xFFFF7A90).withValues(alpha: alpha * 0.65),
-        ],
-      ).createShader(Rect.fromLTWH(startX, 0, width, size.height))
-      ..style = PaintingStyle.fill
-      ..maskFilter = const MaskFilter.blur(BlurStyle.normal, 18);
-    canvas.drawPath(fillPath, fillPaint);
-
-    final strokePaint = Paint()
-      ..color = const Color(
-        0xFFFF6B8A,
-      ).withValues(alpha: active ? 0.22 + liveLevel * 0.28 : 0.08)
-      ..style = PaintingStyle.stroke
-      ..strokeWidth = 2.4 + liveLevel * 3.0
-      ..strokeCap = StrokeCap.round
-      ..strokeJoin = StrokeJoin.round
-      ..maskFilter = const MaskFilter.blur(BlurStyle.normal, 5);
-    canvas.drawPath(topPath, strokePaint);
-    canvas.drawPath(bottomPath, strokePaint);
-  }
-
-  @override
-  bool shouldRepaint(covariant _VoiceWaveUnderlayPainter oldDelegate) {
-    return oldDelegate.samples != samples ||
-        oldDelegate.active != active ||
-        oldDelegate.liveLevel != liveLevel;
-  }
-}
-
 class _VoiceInformationPainter extends CustomPainter {
   const _VoiceInformationPainter({
     required this.samples,