fix: Lots of navigation improvements

lib/widgets/shared/custom_shader_mask.dart

@@ -0,0 +1,60 @@
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+class CustomShaderMask extends StatefulWidget {
+  final Widget child;
+  const CustomShaderMask({required this.child, super.key});
+
+  @override
+  CustomShaderMaskState createState() => CustomShaderMaskState();
+}
+
+class CustomShaderMaskState extends State<CustomShaderMask> {
+  ui.Image? gradientImage;
+
+  @override
+  void initState() {
+    super.initState();
+    _loadImage('assets/gradient.png');
+  }
+
+  Future<void> _loadImage(String assetPath) async {
+    final data = await rootBundle.load(assetPath);
+    final bytes = data.buffer.asUint8List();
+    final codec = await ui.instantiateImageCodec(bytes);
+    final frame = await codec.getNextFrame();
+    setState(() {
+      gradientImage = frame.image;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (gradientImage == null) {
+      return const SizedBox.shrink();
+    }
+
+    return ShaderMask(
+      shaderCallback: (Rect bounds) {
+        final imageWidth = gradientImage!.width.toDouble();
+        final imageHeight = gradientImage!.height.toDouble();
+
+        final scaleX = bounds.width / imageWidth;
+        final scaleY = bounds.height / imageHeight;
+
+        final matrix = Matrix4.diagonal3Values(scaleX, scaleY, 1);
+
+        return ImageShader(
+          gradientImage!,
+          TileMode.clamp,
+          TileMode.clamp,
+          matrix.storage,
+        );
+      },
+      blendMode: BlendMode.dstIn,
+      child: widget.child,
+    );
+  }
+}