fix all errors and make api code perfect for diamond website. in 4 following domains
update core system with complete code and we test it in sandbox.
code should also send stones to ebay when new stones are added.
drop or delete stones from ebay when stones are droped from last update.
select companies i want to send and send them in batch to ebay
write full document for how api works so future coder can undestand how to further develop. detail how the entire system works with files folders and db.