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/list.h

@@ -0,0 +1,51 @@
+// Public nt-lite DDK intrusive list declarations.
+
+#pragma once
+
+#include <stddef.h>
+
+// Doubly-linked intrusive list node.
+typedef struct LIST_ENTRY {
+    struct LIST_ENTRY* Fwd;
+    struct LIST_ENTRY* Bwd;
+} LIST_ENTRY;
+
+#define LIST_INIT(head)     ((head)->Fwd = (head)->Bwd = (head))
+#define LIST_IS_EMPTY(head) ((head)->Fwd == (head))
+
+// Recover the containing struct pointer from an embedded list node.
+#define CONTAINING_RECORD(ptr, type, member) \
+    ((type *)((char *)(ptr) - offsetof(type, member)))
+
+// Inserts a node at the tail of a list.
+static inline void ListInsertTail(LIST_ENTRY* head, LIST_ENTRY* node) {
+    node->Bwd      = head->Bwd;
+    node->Fwd      = head;
+    head->Bwd->Fwd = node;
+    head->Bwd      = node;
+}
+
+// Inserts a node at the head of a list.
+static inline void ListInsertHead(LIST_ENTRY* head, LIST_ENTRY* node) {
+    node->Fwd      = head->Fwd;
+    node->Bwd      = head;
+    head->Fwd->Bwd = node;
+    head->Fwd      = node;
+}
+
+// Removes a node from its current list.
+static inline void ListRemove(LIST_ENTRY* node) {
+    node->Bwd->Fwd = node->Fwd;
+    node->Fwd->Bwd = node->Bwd;
+    node->Fwd = node->Bwd = node;
+}
+
+// Removes and returns the first node in a list, or NULL when empty.
+static inline LIST_ENTRY* ListPopHead(LIST_ENTRY* head) {
+    if (LIST_IS_EMPTY(head))
+        return (LIST_ENTRY*)0;
+
+    LIST_ENTRY* node = head->Fwd;
+    ListRemove(node);
+    return node;
+}