-Added support for scanning AWS S3 buckets via --s3-bucket and optional --s3-prefix

- Added --role-arn and --aws-local-profile flags for S3 authentication alongside KF_AWS_KEY/KF_AWS_SECRET

tests/int_github.rs

@@ -71,6 +71,11 @@ fn test_github_remote_scan() -> Result<()> {
             max_results: 100,
             slack_query: None,
             slack_api_url: Url::parse("https://slack.com/api/").unwrap(),
+            // s3
+            s3_bucket: None,
+            s3_prefix: None,
+            role_arn: None,
+            aws_local_profile: None,
             // Docker image scanning
             docker_image: Vec::new(),
             // git clone / history options