test: add e2e test for importAsset API

Test that importAsset can replace loadBootstrapScriptContent for loading
client entry URLs in both dev and build modes.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: hi-ogawa

packages/plugin-rsc/e2e/import-asset.test.ts

@@ -0,0 +1,38 @@
+import { test } from '@playwright/test'
+import { setupInlineFixture, useFixture } from './fixture'
+import { defineStarterTest } from './starter'
+
+test.describe('viteRsc.importAsset', () => {
+  const root = 'examples/e2e/temp/import-asset'
+  test.beforeAll(async () => {
+    await setupInlineFixture({
+      src: 'examples/starter',
+      dest: root,
+      files: {
+        'src/framework/entry.ssr.tsx': {
+          edit: (s) =>
+            s.replace(
+              `\
+  const bootstrapScriptContent =
+    await import.meta.viteRsc.loadBootstrapScriptContent('index')
+`,
+              `\
+  const asset = await import.meta.viteRsc.importAsset('./entry.browser.tsx', { entry: true })
+  const bootstrapScriptContent = \`import(\${JSON.stringify(asset.url)})\`
+`,
+            ),
+        },
+      },
+    })
+  })
+
+  test.describe('dev', () => {
+    const f = useFixture({ root, mode: 'dev' })
+    defineStarterTest(f)
+  })
+
+  test.describe('build', () => {
+    const f = useFixture({ root, mode: 'build' })
+    defineStarterTest(f)
+  })
+})