fix: Handle missing subgraph inputs gracefully during workflow import (#4985)

When loading workflows, SubgraphNode would throw an error if an input
exists in the serialized data that doesn't exist in the current subgraph
definition. This can happen when:
- Subgraph definitions change after workflows are saved
- Workflows are shared between users with different subgraph versions
- Dynamic inputs were added that don't exist in the base definition

This change converts the hard error to a warning and continues processing,
allowing workflows to load even with mismatched subgraph configurations.

Fixes #4905

Author: christian-byrne

src/lib/litegraph/src/subgraph/SubgraphNode.ts

@@ -266,10 +266,14 @@ export class SubgraphNode extends LGraphNode implements BaseLGraph {
       const subgraphInput = this.subgraph.inputNode.slots.find(
         (slot) => slot.name === input.name
       )
-      if (!subgraphInput)
-        throw new Error(
-          `[SubgraphNode.configure] No subgraph input found for input ${input.name}`
+      if (!subgraphInput) {
+        // Skip inputs that don't exist in the subgraph definition
+        // This can happen when loading workflows with dynamically added inputs
+        console.warn(
+          `[SubgraphNode.configure] No subgraph input found for input ${input.name}, skipping`
         )
+        continue
+      }
 
       this.#addSubgraphInputListeners(subgraphInput, input)