fix: mark subtree of svelte boundary as dynamic (#17468)

.changeset/curly-cats-make.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: mark subtree of svelte boundary as dynamic

packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBoundary.js

@@ -1,6 +1,7 @@
 /** @import { AST } from '#compiler' */
 /** @import { Context } from '../types' */
 import * as e from '../../../errors.js';
+import { mark_subtree_dynamic } from './shared/fragment.js';
 
 const valid = ['onerror', 'failed', 'pending'];
 
@@ -23,5 +24,7 @@ export function SvelteBoundary(node, context) {
 		}
 	}
 
+	mark_subtree_dynamic(context.path);
+
 	context.next();
 }

packages/svelte/tests/runtime-runes/samples/static-boundary/_config.js

@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	html: '<div><div>test</div></div>'
+});

packages/svelte/tests/runtime-runes/samples/static-boundary/main.svelte

@@ -0,0 +1,5 @@
+<div>
+	<svelte:boundary>
+		<div>test</div>
+	</svelte:boundary>
+</div>