Enable parallel groups to be nested one level deep, allowing simultaneous approval between Group B and the Group A/manager OR condition.

Read about the user story here:

APFJ-622: Parallel Groups - OR Condition and Nested StructuresBacklog

Required Changes

1. Allow parallel groups as valid steps, limited to one nesting level.

2. Update UI for parent-child visualization.

Technical Visualization

Parallel Group (AND) {    Group B approval    Parallel Group (OR) {        Group A approval        Manager approval (user step)    }}

Accepted Criteria

• Group B can approve simultaneously with either Group A or manager approval

• Clear status visibility across parent-child structure

• Complete audit trail of approvals