feat(mm): add free-list kernel heap with coalescing

include/heap.h

@@ -0,0 +1,17 @@
+#ifndef FROSTBYTE_HEAP_H
+#define FROSTBYTE_HEAP_H
+
+#include "types.h"
+
+void heapInit(uint64 start, uint64 size);
+void* kmalloc(usize size);
+void kfree(void* pointer);
+void* krealloc(void* pointer, usize size);
+
+uint64 heapUsed(void);
+uint64 heapTotal(void);
+uint64 heapFreeBytes(void);
+uint64 heapLargestFree(void);
+uint64 heapBlockCount(void);
+
+#endif