feat(fs): add VFS, initrd, and filesystem interface headers

include/initrd.h

@@ -0,0 +1,17 @@
+#ifndef FROSTBYTE_INITRD_H
+#define FROSTBYTE_INITRD_H
+
+#include "types.h"
+
+typedef struct UstarEntry {
+    const char* name;
+    const uint8* data;
+    uint64 size;
+    bool isDir;
+} UstarEntry;
+
+void initrdInit(uint64 start, uint64 end);
+uint32 initrdCount(void);
+bool initrdAt(uint32 index, UstarEntry* out);
+
+#endif