adding an explicit tests

packages/svelte/tests/runtime-runes/samples/runes-user-land/ExplicitLegacy.svelte

@@ -0,0 +1,6 @@
+<svelte:options runes={false} />
+<script>
+	export let count = 99;
+</script>
+
+<p class="explicit-legacy">{count}</p>

packages/svelte/tests/runtime-runes/samples/runes-user-land/ExplicitRunes.svelte

@@ -0,0 +1,6 @@
+<svelte:options runes={true} />
+<script>
+	let count = $state(42);
+</script>
+
+<p class="explicit-runes">{count}</p>

packages/svelte/tests/runtime-runes/samples/runes-user-land/_config.js

@@ -6,6 +6,9 @@ export default test({
 	},
 
 	test({ assert, target }) {
-		assert.htmlEqual(target.innerHTML, '<p>1</p>');
+		assert.htmlEqual(
+			target.innerHTML,
+			'<p>1</p><p class="explicit-runes">42</p><p class="explicit-legacy">99</p>'
+		);
 	}
 });

packages/svelte/tests/runtime-runes/samples/runes-user-land/main.svelte

@@ -1,5 +1,10 @@
 <script>
+	import ExplicitRunes from './ExplicitRunes.svelte';
+	import ExplicitLegacy from './ExplicitLegacy.svelte';
+
 	let count = $state(1);
 </script>
 
 <p>{count}</p>
+<ExplicitRunes />
+<ExplicitLegacy />