fix: replace .npmrc with pnpm-workspace.yaml for build config

pnpm-workspace.yaml is the canonical location for allowBuilds
in pnpm v10+, and the package.json trailing comma was cleaned up.

package.json

@@ -40,5 +40,5 @@
     "prettier": "^3.8.0",
     "typescript": "~5.9.3",
     "vite": "^7.3.1"
-  },
+  }
 }