Remove old unique index on device_id in mobile_devices migration to allow multiple users to share the same device.

db/migrate/20250702173231_fix_mobile_devices_unique_constraint.rb

@@ -2,8 +2,8 @@ class FixMobileDevicesUniqueConstraint < ActiveRecord::Migration[7.2]
   def change
     # Remove the old unique index on device_id only
     remove_index :mobile_devices, :device_id, if_exists: true
-    
+
     # The composite unique index on user_id and device_id already exists
     # This allows the same device_id to be used by different users
   end
-end
+end