removed duplicate code causing bugs

[paullizer]

Bug Fixes

• Manage Group Page Duplicate Code and Error Handling Fix
  • Fixed multiple code quality and user experience issues in the Manage Group page JavaScript.
  • Duplicate Event Handlers: Removed duplicate event handler registrations (lines 96-127) for .select-user-btn, .remove-member-btn, .change-role-btn, .approve-request-btn, and .reject-request-btn that were causing multiple event firings.
  • Duplicate HTML in Actions Column: Fixed member action buttons rendering duplicate attributes as visible text instead of functional buttons, causing raw HTML/CSS class names to display in the Actions column.
  • Duplicate Pending Request Buttons: Removed duplicate Approve and Reject buttons in pending requests table that were appearing twice per request.
  • Enhanced Error Handling: Improved setRole() and removeMember() functions with specific error messages for 404 (member not found) and 403 (permission denied) errors, automatic member list refresh on 404, and user-friendly toast notifications instead of generic alerts.
  • Removed Duplicate Comment: Cleaned up duplicate "Render user-search results" comment.
  • Impact: Member management buttons now render and function correctly, provide better error feedback, and auto-recover from stale member data.
  • (Ref: manage_group.js, event handler deduplication, error handling improvements, toast notifications)