Make the sidebar resizer pointer target larger and have it ignore non-primary pointer events

css/80_app.css

@@ -771,9 +771,9 @@ a.hide-toggle {
 .sidebar-resizer {
     position: absolute;
     top: 0;
-    right: -6px;
+    right: -10px;
+    width: 10px;
     height: 100%;
-    width: 6px;
     cursor: col-resize;
     /* disable drag-to-select */
     user-select: none;

modules/ui/sidebar.js

@@ -59,6 +59,8 @@ export function uiSidebar(context) {
         function pointerdown() {
             if (downPointerId) return;
 
+            if ('button' in d3_event && d3_event.button !== 0) return;
+
             downPointerId = d3_event.pointerId || 'mouse';
 
             lastClientX = d3_event.clientX;