message: [terminal] Grid: some little rewrites for better readability.
diff: @@ -605,8 +605,10 @@ CellLocation Grid<Cell>::growLines(LineCount _newHeight, CellLocation _cursor)
  Require(*totalLinesToExtend >= 0);
  // ? Require(linesToTakeFromSavedLines == LineCount(0));
  - auto const linesToFill =
  - max(0, unbox<int>(maxHistoryLineCount_ + _newHeight) - static_cast<int>(lines_.size()));
  + auto const newTotalLineCount = maxHistoryLineCount_ + _newHeight;
  + auto const currentTotalLineCount = LineCount(lines_.size());
  + auto const linesToFill = max(0, *newTotalLineCount - *currentTotalLineCount);
  +
  for ([[maybe_unused]] auto const _: ranges::views::iota(0, linesToFill))
  lines_.emplace_back(pageSize_.columns, wrappableFlag, GraphicsAttributes {});
  