Rearrange project files.

include/internal/vase/buffer/original.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "buffer.h"
+#include "pch.h"
+
+struct OriginalBuffer : Buffer {
+  const char *buf;
+  uint64_t len;
+  int fd = -1;
+
+  OriginalBuffer(std::filesystem::path base_dir);
+  ~OriginalBuffer();
+
+  void initialize();
+  const char *read(uint64_t pos) override;
+  uint64_t length() override;
+};