introduce a stable NTL_DDK driver ABI to replace direct HAL_API and kernel-header access in drivers, add code/kernel/io_ddk.c and code/public/ntlite/ddk/ headers, change DriverEntry to take (const NTL_DDK*, NTL_DRIVER_INIT*), update kmain to build the DDK once via IoInitializeDdk/IoGetDdk and hand it to both boot and runtime drivers, downgrade code/public/ntlite/ddi/io_driver.h to a legacy I/O model header pulling from ntlite/ddk instead of kernel internals, move code/third_party/lwip into code/drivers/net/lwip/third_party, fix up lwip_sources.txt and build.c include paths to match, split build.c's single CFLAGS macro into COMMON/KERNEL/USER/BOOT/DRIVER cflags.

code/public/ntlite/ddk/async.h

@@ -0,0 +1,52 @@
+// Public nt-lite DDK asynchronous request declarations.
+
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+#include <ntlite/status.h>
+#include <ntlite/ddk/list.h>
+#include <ntlite/ddk/object.h>
+
+struct EVENT;
+struct KAPC;
+struct IRP;
+typedef struct MM_LOCKED_USER_BUFFER MM_LOCKED_USER_BUFFER;
+
+typedef struct IO_STATUS_BLOCK {
+    volatile KSTATUS Status;
+    volatile size_t Information;
+} IO_STATUS_BLOCK;
+
+typedef enum IO_ASYNC_REQUEST_STATE {
+    IoAsyncRequestQueued = 0,
+    IoAsyncRequestRunning = 1,
+    IoAsyncRequestCompleted = 2,
+    IoAsyncRequestCancelled = 3,
+} IO_ASYNC_REQUEST_STATE;
+
+typedef struct IO_ASYNC_REQUEST_OBJECT IO_ASYNC_REQUEST_OBJECT;
+
+typedef void (*IO_ASYNC_REQUEST_CLEANUP_ROUTINE)(IO_ASYNC_REQUEST_OBJECT* request,
+                                                 void* context);
+typedef KSTATUS (*IO_ASYNC_REQUEST_CANCEL_ROUTINE)(IO_ASYNC_REQUEST_OBJECT* request,
+                                                   void* context);
+
+struct IO_ASYNC_REQUEST_OBJECT {
+    OBJECT Header;
+    LIST_ENTRY Link;
+    IO_ASYNC_REQUEST_STATE State;
+    uint8_t CancelRequested;
+    struct EVENT* WaitEvent;
+    struct EVENT* CompletionEvent;
+    struct KAPC* CompletionApc;
+    IO_STATUS_BLOCK* Iosb;
+    IO_STATUS_BLOCK IosbSnapshot;
+    MM_LOCKED_USER_BUFFER* LockedBuffer;
+    MM_LOCKED_USER_BUFFER* LockedIosb;
+    struct IRP* Irp;
+    IO_ASYNC_REQUEST_CLEANUP_ROUTINE CleanupRoutine;
+    void* CleanupContext;
+    IO_ASYNC_REQUEST_CANCEL_ROUTINE CancelRoutine;
+    void* CancelContext;
+};