fix: Assign UUID when creating table metadata (#713)

Author: WZhuo

src/iceberg/table_metadata.cc

@@ -224,7 +224,8 @@ Result<std::unique_ptr<TableMetadata>> TableMetadata::Make(
   ICEBERG_RETURN_UNEXPECTED(PropertyUtil::ValidateCommitProperties(properties));
 
   return TableMetadataBuilder::BuildFromEmpty(format_version)
-      ->SetLocation(location)
+      ->AssignUUID()
+      .SetLocation(location)
       .SetCurrentSchema(std::move(fresh_schema), last_column_id)
       .SetDefaultPartitionSpec(std::move(fresh_spec))
       .SetDefaultSortOrder(std::move(fresh_order))

src/iceberg/test/table_metadata_builder_test.cc

@@ -36,6 +36,7 @@
 #include "iceberg/test/matchers.h"
 #include "iceberg/transform.h"
 #include "iceberg/type.h"
+#include "iceberg/util/uuid.h"
 
 namespace iceberg {
 
@@ -102,6 +103,7 @@ TEST(TableMetadataTest, Make) {
 
   ICEBERG_UNWRAP_OR_FAIL(
       auto metadata, TableMetadata::Make(*Schema, *spec, *order, "s3://bucket/test", {}));
+  EXPECT_THAT(Uuid::FromString(metadata->table_uuid), IsOk());
   // Check schema fields
   ASSERT_EQ(1, metadata->schemas.size());
   auto fields = metadata->schemas[0]->fields() | std::ranges::to<std::vector>();