checkpoint boundary selection work

Author: stewartoallen

src/void/sketch/geometry.js

@@ -333,7 +333,10 @@ function resolveDerivedEdgeCandidate(event, intersections, feature) {
     const bestSegDist = this.distanceToSegmentPx(vp.x, vp.y, pwa?.x || 0, pwa?.y || 0, pwb?.x || 0, pwb?.y || 0);
     // Only treat as edge-hover when pointer is genuinely near the edge.
     // Otherwise keep face-hover path active so full boundary preview renders.
-    if (!Number.isFinite(bestSegDist) || bestSegDist > (SKETCH_HIT_LINE_PX * 1.25)) {
+    // Edge mode should only activate when genuinely near a boundary.
+    // Otherwise allow face mode to show the full boundary set.
+    const edgeHoverPx = Math.max(2.5, SKETCH_HIT_LINE_PX * 0.65);
+    if (!Number.isFinite(bestSegDist) || bestSegDist > edgeHoverPx) {
         return null;
     }
     const pointHits = [];

src/void/sketch/pointer.js

@@ -254,9 +254,15 @@ function handleSketchHover(event, intersections) {
 
     const hit = this.resolveSketchHit(event, intersections, feature);
     const hasIntersections = Array.isArray(intersections) && intersections.length > 0;
-    let derived = hasIntersections
-        ? this.resolveDerivedEdgeCandidate(event, intersections, feature)
-        : (this.hoveredDerivedCandidate || null);
+    const primary = hasIntersections
+        ? (this.getPrimarySurfaceHitFromIntersections?.(intersections) || null)
+        : null;
+    let derived = null;
+    if (hasIntersections && primary?.type === 'solid-edge') {
+        derived = this.resolveDerivedEdgeCandidate(event, intersections, feature);
+    } else if (!hasIntersections) {
+        derived = this.hoveredDerivedCandidate || null;
+    }
     if (hit?.id) {
         // Current sketch entities take priority over any behind-surface derive targets.
         derived = null;