Add the missing file which was causing build failures. Adjust the constants so

that we can fit a complete track into a physical sector (which is truncated
slightly due to the index gap).

lib/sector.cc

@@ -0,0 +1,14 @@
+#include "globals.h"
+#include "sector.h"
+#include "fmt/format.h"
+
+const std::string Sector::statusToString(Status status)
+{
+    switch (status)
+    {
+        case Status::OK:           return "OK";
+        case Status::BAD_CHECKSUM: return "bad checksum";
+        case Status::MISSING:      return "sector not found";
+        default:                   return fmt::format("unknown error {}", status);
+    }
+}