message: [terminal] Terminal: Adds convenience helper isCursorInViewport().
diff: @@ -204,6 +204,10 @@ class Terminal
  return insideVerticalMargin && insideHorizontalMargin;
  }
  + [[nodiscard]] bool isCursorInViewport() const noexcept
  + {
  + return viewport().isLineVisible(cursor().position.line);
  + }
  // }}}
  constexpr ImageSize cellPixelSize() const noexcept { return state_.cellPixelSize; }
  