Merge Sorted Customer ID Arrays

Problem

Given two sorted integer arrays arr1 and arr2, each representing customer IDs in non-decreasing order, return a new sorted array containing all unique IDs that appear in either array. The result must not contain duplicates, even if the same ID appears multiple times within one array or across both arrays.

Constraints

• 0 <= len(arr1), len(arr2) <= 10^5
• -10^9 <= arr1[i], arr2[i] <= 10^9
• arr1 and arr2 are sorted in non-decreasing order