Consolidate organizerAdmitAndAddWithVisibility() and
memberAddContactWithVisibility() into a single unified method
processSelectedMembers() that handles both organizer and member
modes based on the isOrganizer prop.
- Remove redundant handleMainAction() wrapper method
- Update template to call processSelectedMembers directly
- Reduce code duplication by ~30% (140 lines → 98 lines)
- Maintain identical functionality for both modes
This simplifies the component structure and makes the processing
logic easier to maintain.