iceberg: keep version-hint.text out of remove_orphans (#11867) (#11871)

Generated with [Devin](https://devin.ai)

Co-authored-by: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

weed/worker/tasks/iceberg/operations.go

@@ -342,6 +342,9 @@ func collectOrphanCandidates(
 	}
 
 	referencedFiles[path.Join("metadata", metadataFileName)] = struct{}{}
+	// Table-root readers (DuckDB iceberg_scan, Hadoop tables) open this to find
+	// the current metadata; nothing in the metadata references it.
+	referencedFiles[path.Join("metadata", "version-hint.text")] = struct{}{}
 	for mle := range meta.PreviousFiles() {
 		referencedFiles[mle.MetadataFile] = struct{}{}
 	}

weed/worker/tasks/iceberg/statistics_orphans_test.go

@@ -57,6 +57,7 @@ func TestOrphanCleanupKeepsStatisticsFiles(t *testing.T) {
 	filer.PutFile(metaDir, "stats-1.puffin", old)
 	filer.PutFile(metaDir, "partition-stats-1.parquet", old)
 	filer.PutFile(metaDir, "stats-0.puffin", old) // superseded: a real orphan
+	filer.PutFile(metaDir, "version-hint.text", old)
 
 	candidates, err := collectOrphanCandidates(context.Background(), filer.Client, bucket, path.Join(namespace, tbl),
 		meta, "v1.metadata.json", 1)
@@ -70,7 +71,7 @@ func TestOrphanCleanupKeepsStatisticsFiles(t *testing.T) {
 	if !doomed["stats-0.puffin"] {
 		t.Fatalf("expected the unreferenced stats-0.puffin to be an orphan, got %v", doomed)
 	}
-	for _, name := range []string{"stats-1.puffin", "partition-stats-1.parquet", "v1.metadata.json"} {
+	for _, name := range []string{"stats-1.puffin", "partition-stats-1.parquet", "v1.metadata.json", "version-hint.text"} {
 		if doomed[name] {
 			t.Errorf("%s is referenced by the table metadata and must not be an orphan", name)
 		}