[1.24.x] Cherry-pick post-1.24.2 fixes including subgraph improvements (#4672)

Co-authored-by: filtered <176114999+webfiltered@users.noreply.github.com>
Co-authored-by: Terry Jia <terryjia88@gmail.com>
Co-authored-by: github-actions <github-actions@github.com>
Co-authored-by: Jin Yi <jin12cc@gmail.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Comfy Org PR Bot <snomiao+comfy-pr@gmail.com>

src/utils/litegraphUtil.ts

@@ -153,7 +153,10 @@ export function migrateWidgetsValues<TWidgetValue>(
  * @param graph - The graph to fix links for.
  */
 export function fixLinkInputSlots(graph: LGraph) {
+  // Note: We can't use forEachNode here because we need access to the graph's
+  // links map at each level. Links are stored in their respective graph/subgraph.
   for (const node of graph.nodes) {
+    // Fix links for the current node
     for (const [inputIndex, input] of node.inputs.entries()) {
       const linkId = input.link
       if (!linkId) continue
@@ -163,6 +166,11 @@ export function fixLinkInputSlots(graph: LGraph) {
 
       link.target_slot = inputIndex
     }
+
+    // Recursively fix links in subgraphs
+    if (node.isSubgraphNode?.() && node.subgraph) {
+      fixLinkInputSlots(node.subgraph)
+    }
   }
 }