feat: settings version display, complete shortcut list, Ctrl fine zoom (v1.7.0)

lib/widgets/image_canvas.dart

@@ -233,7 +233,7 @@ class ImageCanvasState extends State<ImageCanvas> {
     final double vy = _angle == 0 ? e.localPosition.dy : _vpSize.height / 2;
     final double cx = (vx - _tx) / _sc;
     final double cy = (vy - _ty) / _sc;
-    const double factor = 1.1;
+    final double factor = _ctrlPressed ? 1.01 : 1.1;
     final double rawSc = _sc * (e.scrollDelta.dy < 0 ? factor : 1.0 / factor);
     final double newSc = rawSc.clamp(1.0, 20.0);
     if (_angle == 0) {