fix: add function overloads for reply/send to narrow return types

When react is not provided, return type is now correctly inferred as
APIPromise (with asResponse/withResponse methods) instead of the union
type APIPromise | Promise.

Author: R44VC0RP

src/resources/emails.ts

@@ -51,6 +51,12 @@ export class Emails extends APIResource {
    *
    * Note: When using the `react` option, this method returns a Promise instead of APIPromise.
    */
+  reply(
+    id: string,
+    body: EmailReplyParams & { react: unknown },
+    options?: RequestOptions,
+  ): Promise<EmailReplyResponse>;
+  reply(id: string, body: EmailReplyParams, options?: RequestOptions): APIPromise<EmailReplyResponse>;
   reply(
     id: string,
     body: EmailReplyParams,
@@ -87,6 +93,8 @@ export class Emails extends APIResource {
    *
    * Note: When using the `react` option, this method returns a Promise instead of APIPromise.
    */
+  send(body: EmailSendParams & { react: unknown }, options?: RequestOptions): Promise<EmailSendResponse>;
+  send(body: EmailSendParams, options?: RequestOptions): APIPromise<EmailSendResponse>;
   send(
     body: EmailSendParams,
     options?: RequestOptions,