[Breaking change] add dispose method to shape

lib/src/effects/effect.dart

@@ -183,7 +183,7 @@ abstract class Effect<T extends AnimatedParticle> {
   /// Terminates the effect when all emissions are complete and no particles remain active.
   void _killEffectWhenOver() {
     if (_isEmissionOver()) {
-      kill();
+      dispose();
     }
   }
 
@@ -245,10 +245,11 @@ abstract class Effect<T extends AnimatedParticle> {
   ///
   /// This method transitions the effect to the killed state, stops emission,
   /// and clears all active particles and callbacks.
-  void kill() {
+  void dispose() {
     stop(cancel: true);
     _updateState(EffectState.killed);
     postEffectCallback = null;
+    particleConfiguration.dispose();
   }
 
   /// Helper method to generate a random distance

lib/src/particles/particle_configuration.dart

@@ -35,4 +35,8 @@ class ParticleConfiguration {
 
   /// Effect to trigger once particle travel is over.
   final Effect<AnimatedParticle> Function(Particle, Size surfaceSize)? postEffectBuilder;
+
+  void dispose() {
+    shape.dispose();
+  }
 }

lib/src/particles/shape.dart

@@ -35,6 +35,8 @@ sealed class Shape {
     Particle particle,
     ui.Image defaultShapes,
   );
+
+  void dispose();
 }
 
 /// Represents a circular shape for rendering particles.
@@ -67,6 +69,9 @@ class CircleShape extends Shape {
     final color = particle.color;
     return (image: defaultShapes, rect: rect, transform: transform, color: color);
   }
+
+  @override
+  void dispose() {}
 }
 
 /// Represents a shape based on an image for rendering particles.
@@ -105,6 +110,11 @@ class ImageShape extends Shape {
     final color = particle.color;
     return (image: image, rect: rect, transform: transform, color: color);
   }
+
+  @override
+  void dispose() {
+    image.dispose();
+  }
 }
 
 /// Represents a shape based on an asset image for rendering particles.
@@ -159,6 +169,11 @@ class ImageAssetShape extends Shape {
     }
     return imageShape.computeTransformation(particle, defaultShapes);
   }
+
+  @override
+  void dispose() {
+    _imageShape?.dispose();
+  }
 }
 
 /// Represents a square shape for rendering particles.
@@ -191,4 +206,7 @@ class SquareShape extends Shape {
     final color = particle.color;
     return (image: defaultShapes, rect: rect, transform: transform, color: color);
   }
+
+  @override
+  void dispose() {}
 }