Implement order reassign modal

Problem/Motivation

The current order reassignment workflow disrupts CSR productivity by redirecting users to a separate page when clicking "Reassign Order." This navigation breaks workflow continuity and reduces efficiency during order management tasks.

Steps to reproduce

• Navigate to an order view page as a CSR
• Click the "Reassign Order" action link
• Notice redirection to a separate reassignment page
• Experience workflow disruption and context loss

Proposed resolution

Implement a modal-based solution for order reassignment that maintains context and eliminates navigation friction. The modal will provide the same functionality as the current separate page while keeping CSRs in their workspace.

Remaining tasks

• Convert "Reassign Order" action to open modal instead of redirecting
• Implement modal interface with current assignee display
• Add customer search functionality within modal
• Enable new customer creation directly from modal
• Maintain all existing form fields and functionality in modal format
• Implement responsive design for cross-device compatibility
• Ensure automatic modal closure upon successful reassignment
• Add order view refresh after successful assignment
• Implement confirmation prompt for unsaved work dismissal
• Apply existing validation rules to modal form
• Preserve all current API calls and data handling