fix(create): update React template mdx package for React 19

Fixes #398

Author: tannerlinsley

.changeset/fair-students-cough.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/create': patch
+---
+
+Bump `@content-collections/mdx` in the React base template to `^0.2.2` so new projects install cleanly with React 19.

packages/create/src/frameworks/react/project/base/package.json

@@ -24,7 +24,7 @@
   "devDependencies": {
     "@content-collections/core": "^0.13.1",
     "@content-collections/markdown": "^0.1.4",
-    "@content-collections/mdx": "^0.1.2",
+    "@content-collections/mdx": "^0.2.2",
     "@content-collections/vite": "^0.2.8",
     "@tailwindcss/typography": "^0.5.16",
     "@tanstack/devtools-vite": "^0.3.11",