feat: extend slab with KmemCache and SpinLock

include/vec.h

@@ -0,0 +1,46 @@
+#ifndef FROSTBYTE_VEC_H
+#define FROSTBYTE_VEC_H
+
+#include "types.h"
+
+/*
+ * Vec: a growable, type-erased array backed by the kernel heap. Elements
+ * are stored by value (memcpy'd in and out), sized by elemSize so a single
+ * implementation serves every element type without void* indirection or
+ * per-type code generation.
+ */
+
+typedef struct Vec {
+    uint8* data;
+    usize elemSize;
+    usize length;
+    usize capacity;
+} Vec;
+
+void vecInit(Vec* v, usize elemSize);
+void vecFree(Vec* v);
+
+/* Ensures capacity for at least newCapacity elements. Returns false only
+   if the underlying allocation failed (existing contents are untouched). */
+bool vecReserve(Vec* v, usize newCapacity);
+
+bool vecPush(Vec* v, const void* elem);
+/* Removes and copies out the last element. False (and *outElem untouched)
+   when the vector is empty; outElem may be nullptr to just drop it. */
+bool vecPop(Vec* v, void* outElem);
+
+/* Pointer into the backing storage; nullptr if index is out of range.
+   Invalidated by any push/insert/remove/reserve that reallocates. */
+void* vecAt(Vec* v, usize index);
+bool vecSet(Vec* v, usize index, const void* elem);
+
+bool vecInsert(Vec* v, usize index, const void* elem);
+bool vecRemove(Vec* v, usize index, void* outElem);
+
+void vecClear(Vec* v);
+
+usize vecLen(const Vec* v);
+usize vecCap(const Vec* v);
+bool vecIsEmpty(const Vec* v);
+
+#endif