fix(studio): downgrade @vitejs/plugin-react to ^5.2.0 for Vite 7 compatibility

@vitejs/plugin-react v6 requires Vite 8+ and fails with ERR_PACKAGE_PATH_NOT_EXPORTED
when paired with Vite 7. v5.2.0 explicitly supports Vite 4–8.

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

apps/studio/package.json

@@ -54,7 +54,7 @@
     "@tailwindcss/postcss": "^4.2.1",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
-    "@vitejs/plugin-react": "^6.0.1",
+    "@vitejs/plugin-react": "^5.2.0",
     "autoprefixer": "^10.4.27",
     "happy-dom": "^20.8.4",
     "hono": "^4.12.8",