Update react monorepo to v19

Author: renovate[bot]

package-lock.json

@@ -13,17 +13,17 @@
     "@netlify/functions": "^3.0.0",
     "@octokit/webhooks-types": "^7.6.1",
     "next": "15.3.1",
-    "react": "^18",
-    "react-dom": "^18",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
     "react-icons": "^5.4.0",
     "react-markdown": "^9.0.3",
     "remark-gfm": "^4.0.0"
   },
   "devDependencies": {
     "@tailwindcss/typography": "^0.5.16",
     "@types/node": "^20",
-    "@types/react": "^18",
-    "@types/react-dom": "^18",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
     "eslint": "^9.0.0",
     "eslint-config-next": "15.3.1",
     "postcss": "^8",