feat(workflow): improve group node interaction handling

- Enhanced `useNodesInteractions` to better manage group node handlers and connections, ensuring accurate identification of leaf nodes and their branches.
- Updated logic to create handlers based on node connections, differentiating between internal and external connections.
- Refined initial node setup to include target branches for group nodes, improving the overall interaction model for grouped elements.

web/app/components/workflow/utils/workflow-init.ts

@@ -380,6 +380,16 @@ export const initialNodes = (originNodes: Node[], originEdges: Edge[]) => {
       })
     }
 
+    if (node.data.type === BlockEnum.Group) {
+      const groupData = node.data as GroupNodeData
+      if (groupData.handlers?.length) {
+        node.data._targetBranches = groupData.handlers.map(handler => ({
+          id: handler.id,
+          name: handler.label || handler.id,
+        }))
+      }
+    }
+
     if (node.data.type === BlockEnum.Iteration) {
       const iterationNodeData = node.data as IterationNodeType
       iterationNodeData._children = iterationOrLoopNodeMap[node.id] || []