Externalize all React entrypoints

Fixes React 19 compat issues due to bundling JSX dev runtime.
Also enables future applications of React Compiler to bundled MDX.

Author: eps1lon

src/client.js

@@ -1,5 +1,6 @@
 import * as React from 'react'
 import * as _jsx_runtime from 'react/jsx-runtime'
+import * as _jsx_dev_runtime from 'react/jsx-dev-runtime'
 import * as ReactDOM from 'react-dom'
 
 /**
@@ -26,7 +27,13 @@ function getMDXComponent(code, globals) {
  *
  */
 function getMDXExport(code, globals) {
-  const scope = {React, ReactDOM, _jsx_runtime, ...globals}
+  const scope = {
+    React,
+    ReactDOM,
+    _jsx_runtime:
+      process.env.NODE_ENV === 'production' ? _jsx_runtime : _jsx_dev_runtime,
+    ...globals,
+  }
   // eslint-disable-next-line
   const fn = new Function(...Object.keys(scope), code)
   return fn(...Object.values(scope))

src/index.js

@@ -199,6 +199,14 @@ async function bundleMDX({
             varName: '_jsx_runtime',
             type: 'cjs',
           },
+          'react/jsx-dev-runtime': {
+            varName: '_jsx_runtime',
+            type: 'cjs'
+          },
+          'react/compiler-runtime': {
+            varName: '_react_compiler_runtime',
+            type: 'cjs'
+          }
         }),
         // eslint-disable-next-line new-cap
         NodeResolvePlugin({