improve u_gamma support & update default dense-render-distance value

src/settings.hpp

@@ -82,7 +82,7 @@ struct GraphicsSettings {
     /// @brief Shadows quality
     IntegerSetting shadowsQuality {0, 0, 3};
     /// @brief Dense render distance
-    IntegerSetting denseRenderDistance {40, 0, 10'000};
+    IntegerSetting denseRenderDistance {56, 0, 10'000};
 };
 
 struct DebugSettings {