chore(typedoc): mark RequestHandlerExtra as intentionally not exported

AppToolCallback (introduced with the Standard Schema migration) references
the local RequestHandlerExtra alias in its parameter type. The alias is a
private Parameters<> derivation and isn't part of the public API surface,
so add it to intentionallyNotExported alongside AppOptions/MethodSchema.

Author: ochafik

typedoc.config.mjs

@@ -28,7 +28,11 @@ const config = {
   ],
   excludePrivate: true,
   excludeInternal: false,
-  intentionallyNotExported: ["AppOptions", "MethodSchema"],
+  intentionallyNotExported: [
+    "AppOptions",
+    "MethodSchema",
+    "RequestHandlerExtra",
+  ],
   blockTags: [...OptionDefaults.blockTags, "@description"],
   jsDocCompatibility: {
     exampleTag: false,