Native Iceberg scan does not report scan metrics or scan time in the Spark UI #6026

What is the problem the feature request solves?

When Comet runs an Iceberg scan natively (CometIcebergNativeScanExec), the Spark SQL UI does not
show the scan metrics that plain Spark + Iceberg normally shows on the BatchScan node. All the
Iceberg planning numbers show up as 0:

• number of data manifests, scanned/skipped manifests
• number of result/skipped data files
• total data file size
• total planning duration
• all the delete-file counts and sizes

The scan also does not report any "scan time", so there is no way to see how long the native read
took.

Vanilla Iceberg shows all of these (they come from Iceberg's Java planning), so users lose
visibility when Comet takes over the scan.

Expected: the native Iceberg scan node in the Spark UI shows the same planning numbers Iceberg-Java
reports, plus a scan time.

Describe the potential solution

No response

Additional context

No response