fix(package.json): use cjs by default in package.json

Author: dtfiedler

typescript/packages/x402/package.json

@@ -3,7 +3,7 @@
   "version": "0.6.1",
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
-  "types": "./dist/esm/index.d.ts",
+  "types": "./dist/cjs/index.d.ts",
   "scripts": {
     "start": "tsx --env-file=.env index.ts",
     "build": "tsup",