fix: Move NOTE comment to the fetch function it describes

Author: Qard

tests/promise_subclass/mod.js

@@ -7,18 +7,19 @@
  * A Promise subclass with an extra method, similar to Anthropic SDK's APIPromise.
  * The instrumented wrapper must preserve the original return type so callers
  * can still access subclass-specific methods like `.withResponse()`.
- *
- * NOTE: This function is intentionally NOT async. Async functions always wrap
- * their return value in a native Promise, losing the subclass type. The real-
- * world scenario (e.g. Anthropic SDK's APIPromise) uses a non-async function
- * that explicitly constructs and returns a Promise subclass instance.
  */
 class ExtendedPromise extends Promise {
   withResponse () {
     return this.then(result => ({ data: result, response: { status: 200 } }))
   }
 }
 
+/**
+ * NOTE: Intentionally NOT async. Async functions always wrap their return value
+ * in a native Promise, losing the subclass type. The real-world scenario
+ * (e.g. Anthropic SDK's APIPromise) uses a non-async function that explicitly
+ * constructs and returns a Promise subclass instance.
+ */
 function fetch (url) {
   return new ExtendedPromise(resolve => resolve(42))
 }