apacheGH-514: [Parquet] Infer schema when projection is null in ParquetReader

This change enables reading Parquet files without an explicit projection schema.
If `options.projection` is not provided, the reader now infers the Iceberg schema
from the Parquet file's Arrow schema.

*   Modified `src/iceberg/parquet/parquet_reader.cc` to remove the null check for `projection` and add schema inference logic using `FromArrowSchema`.
*   Added `src/iceberg/test/parquet_reader_no_projection_test.cc` to verify the fix.
*   Updated `src/iceberg/CMakeLists.txt` to include `arrow_c_data_guard_internal.cc` and `schema_internal.cc` in the bundle target to resolve linker errors.

Co-authored-by: wgtmac <4684607+wgtmac@users.noreply.github.com>

Author: google-labs-jules[bot]

src/iceberg/CMakeLists.txt

@@ -173,6 +173,7 @@ if(ICEBERG_BUILD_BUNDLE)
   set(ICEBERG_BUNDLE_SOURCES
       arrow/arrow_fs_file_io.cc
       arrow/metadata_column_util.cc
+      arrow_c_data_guard_internal.cc
       avro/avro_data_util.cc
       avro/avro_direct_decoder.cc
       avro/avro_direct_encoder.cc
@@ -185,7 +186,8 @@ if(ICEBERG_BUILD_BUNDLE)
       parquet/parquet_reader.cc
       parquet/parquet_register.cc
       parquet/parquet_schema_util.cc
-      parquet/parquet_writer.cc)
+      parquet/parquet_writer.cc
+      schema_internal.cc)
 
   # Libraries to link with exported libiceberg_bundle.{so,a}.
   set(ICEBERG_BUNDLE_STATIC_BUILD_INTERFACE_LIBS)

src/iceberg/test/parquet_reader_no_projection_test.cc

@@ -20,6 +20,8 @@
 #include <arrow/array.h>
 #include <arrow/c/bridge.h>
 #include <arrow/json/from_string.h>
+#include <arrow/record_batch.h>
+#include <arrow/table.h>
 #include <arrow/type.h>
 #include <gtest/gtest.h>
 
@@ -28,6 +30,7 @@
 #include "iceberg/file_reader.h"
 #include "iceberg/file_writer.h"
 #include "iceberg/parquet/parquet_register.h"
+#include "iceberg/schema.h"
 #include "iceberg/schema_internal.h"
 #include "iceberg/test/matchers.h"
 #include "iceberg/type.h"
@@ -117,7 +120,6 @@ TEST_F(ParquetReaderNoProjectionTest, ReadWithoutProjection) {
   auto reader_result = ReaderFactoryRegistry::Open(
       FileFormatType::kParquet, {.path = temp_parquet_file_, .io = file_io_});
 
-  // This is expected to fail currently
   ASSERT_THAT(reader_result, IsOk())
       << "Failed to create reader: " << reader_result.error().message;
   auto reader = std::move(reader_result.value());