Include path endpoints as extrema in the Extrude node (#3469)

* Include single connected points as extrema in the extrude node

* Update styling of loading indicator

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

frontend/index.html

@@ -44,6 +44,14 @@
 				border: 4px solid #eee;
 				border-color: #eee transparent #eee transparent;
 				animation: spinning-loading-indicator 1s linear infinite;
+
+				@media (prefers-reduced-motion) {
+					border: none;
+					animation: none;
+					content: "Loading…";
+					font-family: Arial, sans-serif;
+					font-size: 24px;
+				}
 			}
 
 			@keyframes spinning-loading-indicator {

node-graph/nodes/vector/src/vector_nodes.rs

@@ -712,7 +712,8 @@ pub mod extrude_algorithms {
 
 		let mut next_segment = vector.segment_domain.next_id();
 		for (index, &point) in points.iter().enumerate().take(first_half_points) {
-			if point != Found::Both {
+			// Extrema are single connected points or points with both positive and negative values
+			if !matches!(point, Found::Both | Found::Positive | Found::Negative) {
 				continue;
 			}