fix: recompute link paths on pan changes to prevent jumping

Pan-x and pan-y changes were not incrementing geometry-version,
so link paths were not recomputed during panning. This caused
links to jump/snap instead of moving smoothly with their nodes.

Author: tilladam

node-editor.slint

@@ -392,8 +392,8 @@ export component NodeEditor {
     }
 
     // === Trigger updates on viewport changes ===
-    changed pan-x => { request-grid-update(); viewport-changed(); }
-    changed pan-y => { request-grid-update(); viewport-changed(); }
+    changed pan-x => { root.geometry-version += 1; request-grid-update(); viewport-changed(); }
+    changed pan-y => { root.geometry-version += 1; request-grid-update(); viewport-changed(); }
     changed zoom => { root.geometry-version += 1; request-grid-update(); viewport-changed(); }
     changed width => { request-grid-update(); }
     changed height => { request-grid-update(); }