Default by spliting addons in 2 parts

packages/sv/src/cli/tests/snapshots/@my-org/sv/src/index.js

@@ -1,5 +1,5 @@
-import { transforms } from '@sveltejs/sv-utils';
 import { defineAddon, defineAddonOptions } from 'sv';
+import { transforms } from './sv-utils.js';
 
 const options = defineAddonOptions()
 	.add('who', {

packages/sv/src/cli/tests/snapshots/@my-org/sv/src/sv-utils.js

@@ -0,0 +1,3 @@
+// This file is a separate entry point (see tsdown.config.js) so that
+// the addon's utilities are published as their own module on npm.
+export * from '@sveltejs/sv-utils';

packages/sv/src/cli/tests/snapshots/@my-org/sv/tsdown.config.js

@@ -1,6 +1,6 @@
 import { defineConfig } from 'tsdown';
 
 export default defineConfig({
-	entry: ['src/index.js'],
+	entry: ['src/index.js', 'src/sv-utils.js'],
 	format: 'esm'
 });

packages/sv/src/create/templates/addon/src/index.js

@@ -1,5 +1,5 @@
-import { transforms } from '@sveltejs/sv-utils';
 import { defineAddon, defineAddonOptions } from 'sv';
+import { transforms } from './sv-utils.js';
 
 const options = defineAddonOptions()
 	.add('who', {

packages/sv/src/create/templates/addon/src/sv-utils.js

@@ -0,0 +1,3 @@
+// This file is a separate entry point (see tsdown.config.js) so that
+// the addon's utilities are published as their own module on npm.
+export * from '@sveltejs/sv-utils';

packages/sv/src/create/templates/addon/tsdown.config.js

@@ -1,6 +1,6 @@
 import { defineConfig } from 'tsdown';
 
 export default defineConfig({
-	entry: ['src/index.js'],
+	entry: ['src/index.js', 'src/sv-utils.js'],
 	format: 'esm'
 });