test: cover the each.js outro path and the flip-back-while-paused case

packages/svelte/tests/runtime-runes/samples/transition-global-nested-resume-each/_config.js

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+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+// #15604 — a removed each item mid-outro must not be resurrected by an ancestor pause/resume
+export default test({
+	test({ assert, target, raf }) {
+		const [remove, fetch] = target.querySelectorAll('button');
+
+		raf.tick(200);
+		assert.equal(target.querySelectorAll('.item').length, 3);
+
+		flushSync(() => remove.click());
+
+		flushSync(() => fetch.click());
+		raf.tick(30);
+
+		flushSync(() => fetch.click());
+		raf.tick(2000);
+
+		const items = [...target.querySelectorAll('.item')].map((el) => el.textContent);
+		assert.deepEqual(items, ['a', 'c']);
+	}
+});

packages/svelte/tests/runtime-runes/samples/transition-global-nested-resume-each/main.svelte

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+<script>
+	import { fade } from 'svelte/transition';
+
+	let fetching = $state(false);
+	let items = $state(['a', 'b', 'c']);
+</script>
+
+<button onclick={() => (items = items.filter((i) => i !== 'b'))}>remove</button>
+<button onclick={() => (fetching = !fetching)}>fetch</button>
+
+{#if fetching}
+	<p>loading</p>
+{:else}
+	<div transition:fade={{ duration: 100 }}>
+		{#each items as item (item)}
+			<div class="item" transition:fade|global={{ duration: 100 }}>{item}</div>
+		{/each}
+	</div>
+{/if}

packages/svelte/tests/runtime-runes/samples/transition-global-nested-resume-flipback/_config.js

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+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+// #15604 companion — flipping the condition back while the ancestor is paused must still revive the element
+export default test({
+	test({ assert, target, raf }) {
+		const [toggle, fetch] = target.querySelectorAll('button');
+
+		raf.tick(200);
+		assert.ok(target.querySelector('.red'));
+
+		flushSync(() => toggle.click());
+
+		flushSync(() => fetch.click());
+		raf.tick(30);
+
+		flushSync(() => toggle.click());
+
+		flushSync(() => fetch.click());
+		raf.tick(2000);
+
+		assert.ok(target.querySelector('.red'));
+	}
+});

packages/svelte/tests/runtime-runes/samples/transition-global-nested-resume-flipback/main.svelte

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+<script>
+	import { fade } from 'svelte/transition';
+
+	let fetching = $state(false);
+	let shown = $state(true);
+</script>
+
+<button onclick={() => (shown = !shown)}>toggle</button>
+<button onclick={() => (fetching = !fetching)}>fetch</button>
+
+{#if fetching}
+	<p>loading</p>
+{:else}
+	<div transition:fade={{ duration: 100 }}>
+		{#if shown}
+			<div class="red" transition:fade|global={{ duration: 100 }}>red</div>
+		{/if}
+	</div>
+{/if}