message: ignore mouse moves when no button is held in SelectionViewportControls
diff: @@ -251,9 +251,14 @@ export class SelectionViewportControls extends PluginUIComponent {
  this.subscribe(this.plugin.behaviors.interaction.selectionMode, () => this.forceUpdate());
  }
  + onMouseMove = (e: React.MouseEvent) => {
  + // ignore mouse moves when no button is held
  + if (e.buttons === 0) e.stopPropagation()
  + }
  +
  render() {
  if (!this.plugin.selectionMode) return null;
  - return <div className='msp-selection-viewport-controls'>
  + return <div className='msp-selection-viewport-controls' onMouseMove={this.onMouseMove}>
  <StructureSelectionActionsControls />
  </div>;
  }
  