feat: implement PS/2 keyboard & shell, dynamic heap (malloc/new), Zero-Copy SHM, and SMP multicore initialization

lib/libc/include/stdlib.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "stddef.h"
+#include "stdint.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void *malloc(size_t size);
+void  free(void *ptr);
+void *calloc(size_t num, size_t size);
+void *realloc(void *ptr, size_t size);
+
+void abort(void);
+void exit(int status);
+
+#ifdef __cplusplus
+}
+#endif