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/event.h

@@ -0,0 +1,45 @@
+// Public nt-lite DDK event declarations.
+
+#pragma once
+
+#include <stdint.h>
+#include <ntlite/status.h>
+#include <ntlite/ddk/list.h>
+#include <ntlite/ddk/object.h>
+#include <ntlite/ddk/sync.h>
+
+typedef enum EVENT_TYPE {
+    EventAutoReset,
+    EventManualReset,
+} EVENT_TYPE;
+
+typedef struct EVENT {
+    OBJECT Header;
+    SPINLOCK Lock;
+    EVENT_TYPE Type;
+    uint32_t Signaled;
+    LIST_ENTRY WaitList;
+    LIST_ENTRY MultiWaitList;
+} EVENT;
+
+// Creates an event object.
+__declspec(dllexport) KSTATUS KeEventCreate(EVENT_TYPE type, uint32_t initialState, EVENT** out);
+
+// Signals an event.
+__declspec(dllexport) void KeSignalEvent(EVENT* event);
+
+// Clears an event.
+__declspec(dllexport) void KeClearEvent(EVENT* event);
+
+// Waits for an event.
+__declspec(dllexport) KSTATUS KeWaitForEvent(EVENT* event, uint8_t alertable);
+
+// Attempts to wait for an event without blocking.
+__declspec(dllexport) KSTATUS KeTryWaitEvent(EVENT* event);
+
+// Waits for one of several events.
+__declspec(dllexport) KSTATUS KeWaitForMultipleEvents(EVENT** events,
+                                                      uint32_t count,
+                                                      uint8_t alertable,
+                                                      uint64_t timeoutMs,
+                                                      uint32_t* signaledIndexOut);