feat: add /exec session overrides

src/auto-reply/reply.ts

@@ -5,6 +5,7 @@ export {
   extractVerboseDirective,
 } from "./reply/directives.js";
 export { getReplyFromConfig } from "./reply/get-reply.js";
+export { extractExecDirective } from "./reply/exec.js";
 export { extractQueueDirective } from "./reply/queue.js";
 export { extractReplyToTag } from "./reply/reply-tags.js";
 export type { GetReplyOptions, ReplyPayload } from "./types.js";