changed all unique_ptr that doesn't have ownership to a const reference

src/curses_output.h

@@ -8,9 +8,9 @@
 
 class curses_output final : public display {
 private:
-        std::unique_ptr<cursor> &curse;
+        const std::unique_ptr<cursor> &curse;
 public:
-        curses_output(std::unique_ptr<cursor> &new_curse);
+        curses_output(const std::unique_ptr<cursor> &new_curse);
 
         void render() override;
         void clear() override;