[fix] laser pointer (#1429)

This PR makes two improvements to the laser pointer:
- it increases the opacity of collaborator lasers
- it fixes a case where a scribble could have no points

### Change Type

- [x] `patch` — Bug Fix

packages/editor/src/lib/components/DefaultScribble.tsx

@@ -19,6 +19,8 @@ export const DefaultScribble: TLScribbleComponent = ({
 	opacity,
 	className,
 }) => {
+	if (!scribble.points.length) return
+
 	const d = getSvgPathFromStroke(
 		getStroke(scribble.points, {
 			size: scribble.size / zoom,

packages/editor/src/lib/components/LiveCollaborators.tsx

@@ -82,7 +82,7 @@ const Collaborator = track(function Collaborator({ userId }: { userId: TLUserId
 					scribble={scribble}
 					color={color}
 					zoom={zoomLevel}
-					opacity={0.1}
+					opacity={scribble.color === 'laser' ? 0.5 : 0.1}
 				/>
 			) : null}
 			{CollaboratorShapeIndicator &&