perf(build): drop arrow/api.h umbrella from vgi_logging.hpp

vgi_logging.hpp is included by ~34 TUs (it hosts the VGI_LOG macros), and
each was parsing the full <arrow/api.h> umbrella (~92k preprocessed lines)
solely because HandleBatchLogMessage declares shared_ptr<arrow::RecordBatch>
/ shared_ptr<arrow::KeyValueMetadata> parameters. Those are forward-declarable
since the header never touches Arrow definitions.

Replace the include with forward declarations and move <arrow/api.h> into
vgi_logging.cpp where the definitions are actually used. Cuts the Arrow
header parse out of every logging-only TU.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: rustyconover

src/include/vgi_logging.hpp

@@ -6,7 +6,14 @@
 
 #include "vgi_platform.hpp" // pid_t (real on POSIX, shim on Windows)
 
-#include <arrow/api.h>
+// Arrow types appear only as shared_ptr parameters below, so forward
+// declarations suffice here. Pulling in the full <arrow/api.h> umbrella from
+// this header is expensive because vgi_logging.hpp is included by ~34 TUs; the
+// definitions are only needed in vgi_logging.cpp.
+namespace arrow {
+class RecordBatch;
+class KeyValueMetadata;
+} // namespace arrow
 
 #include "duckdb/logging/logging.hpp"
 #include "duckdb/logging/log_type.hpp"

src/vgi_logging.cpp

@@ -5,6 +5,8 @@
 #include "vgi_ifunction_connection.hpp"
 #include "yyjson.hpp"
 
+#include <arrow/api.h> // full Arrow definitions for HandleBatchLogMessage (forward-declared in the header)
+
 #include <algorithm>
 #include <atomic>
 #include <chrono>