Transfer Custom Pipeline

Transfer a custom processor to another team. This endpoint allows admins to transfer ownership of a custom processor from one team to another. This is useful for:

1. Beta testing: Create and test processors internally, then transfer to customers
2. Sharing: Move successful processor configurations between teams
3. Updating: Push iterated versions to an existing customer processor (via to_processor_id)

Superusers can transfer any processor regardless of team ownership.