test(01-02): wave-0 setup — install vitest

- Add vitest@^4 to devDependencies (4.1.6 latest stable; 5.x still beta)
- Add "test": "vitest run" npm script
- Run npm install to refresh node_modules and lock file

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -6,7 +6,8 @@
   "scripts": {
     "dev": "vite",
     "build": "tsc && vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run"
   },
   "dependencies": {
     "rrweb": "^2.0.0-alpha.4",
@@ -16,6 +17,7 @@
     "@crxjs/vite-plugin": "^2.0.0-beta.25",
     "@types/chrome": "^0.0.268",
     "typescript": "^5.5.4",
-    "vite": "^5.4.2"
+    "vite": "^5.4.2",
+    "vitest": "^4"
   }
 }