fix: remove invalid vitest workspace config, fix test:storybook script

vitest v4 removed defineWorkspace API, causing CI failure.
No .stories.test.* files exist, so test:storybook is a no-op.

packages/design-system/package.json

@@ -14,7 +14,7 @@
     "test": "vitest run --project unit",
     "storybook": "storybook dev -p 6006 --no-open",
     "build-storybook": "storybook build",
-    "test:storybook": "vitest run --project storybook",
+    "test:storybook": "echo \"No storybook tests yet\"",
     "lint": "eslint \"src/**/*.{ts,tsx}\""
   },
   "peerDependencies": {

packages/design-system/vitest.workspace.ts

@@ -1,19 +0,0 @@
-import { defineWorkspace } from 'vitest/config';
-
-export default defineWorkspace([
-  'vitest.config.ts',
-  {
-    test: {
-      name: 'storybook',
-      browser: {
-        enabled: true,
-        name: 'chromium',
-        provider: 'playwright',
-        headless: true,
-      },
-      setupFiles: ['./.storybook/vitest.setup.ts'],
-      include: ['src/**/*.stories.test.{ts,tsx}'],
-      passWithNoTests: true,
-    },
-  },
-]);