refactor(client): extract interval logic to a composable function

あと`onUnmounted`を`onMounted`内で呼んでいたりしたのを修正したりとか

packages/client/src/components/sparkle.vue

@@ -33,7 +33,8 @@
 	</svg>
 	-->
 	<svg v-for="particle in particles" :key="particle.id" :width="width" :height="height" :viewBox="`0 0 ${width} ${height}`" xmlns="http://www.w3.org/2000/svg">
-		<path style="transform-origin: center; transform-box: fill-box;"
+		<path
+			style="transform-origin: center; transform-box: fill-box;"
 			:transform="`translate(${particle.x} ${particle.y})`"
 			:fill="particle.color"
 			d="M29.427,2.011C29.721,0.83 30.782,0 32,0C33.218,0 34.279,0.83 34.573,2.011L39.455,21.646C39.629,22.347 39.991,22.987 40.502,23.498C41.013,24.009 41.653,24.371 42.354,24.545L61.989,29.427C63.17,29.721 64,30.782 64,32C64,33.218 63.17,34.279 61.989,34.573L42.354,39.455C41.653,39.629 41.013,39.991 40.502,40.502C39.991,41.013 39.629,41.653 39.455,42.354L34.573,61.989C34.279,63.17 33.218,64 32,64C30.782,64 29.721,63.17 29.427,61.989L24.545,42.354C24.371,41.653 24.009,41.013 23.498,40.502C22.987,39.991 22.347,39.629 21.646,39.455L2.011,34.573C0.83,34.279 0,33.218 0,32C0,30.782 0.83,29.721 2.011,29.427L21.646,24.545C22.347,24.371 22.987,24.009 23.498,23.498C24.009,22.987 24.371,22.347 24.545,21.646L29.427,2.011Z"
@@ -73,14 +74,15 @@ export default defineComponent({
 		const width = ref(0);
 		const height = ref(0);
 		const colors = ['#FF1493', '#00FFFF', '#FFE202', '#FFE202', '#FFE202'];
+		let stop = false;
+		let ro: ResizeObserver | undefined;
 
 		onMounted(() => {
-			const ro = new ResizeObserver((entries, observer) => {
+			ro = new ResizeObserver((entries, observer) => {
 				width.value = el.value?.offsetWidth + 64;
 				height.value = el.value?.offsetHeight + 64;
 			});
 			ro.observe(el.value);
-			let stop = false;
 			const add = () => {
 				if (stop) return;
 				const x = (Math.random() * (width.value - 64));
@@ -104,10 +106,11 @@ export default defineComponent({
 				}, 500 + (Math.random() * 500));
 			};
 			add();
-			onUnmounted(() => {
-				ro.disconnect();
-				stop = true;
-			});
+		});
+		
+		onUnmounted(() => {
+			if (ro) ro.disconnect();
+			stop = true;
 		});
 
 		return {