fix: implement S3 listBuckets to actually list buckets

- Add @aws-sdk/client-s3 dependency for direct S3 operations
- Fix listBuckets handler which was hardcoded to return empty array
- Now properly queries S3 and returns actual bucket names

package.json

@@ -27,6 +27,7 @@
     "@api.global/typedrequest": "^3.2.5",
     "@api.global/typedrequest-interfaces": "^3.0.19",
     "@api.global/typedserver": "^8.3.0",
+    "@aws-sdk/client-s3": "^3.975.0",
     "@design.estate/dees-catalog": "^3.37.0",
     "@design.estate/dees-element": "^2.1.5",
     "@push.rocks/early": "^4.0.4",