fix(deps): update react monorepo to v19 (major) (#71)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -26,8 +26,8 @@
     "next": "^14.2.4",
     "nextra": "^3.0.0",
     "nextra-theme-docs": "^3.0.0",
-    "react": "^18.3.1",
-    "react-dom": "^18.3.1",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
     "react-icons": "^5.2.1",
     "shiki": "^3.0.0"
   },