Remove unconditional OrderCreation clone in post_order_handler

[ashleychandy]

Summary

Eliminates the order.clone() call in post_order_handler by extracting a subset of fields
before consuming the order into add_order.

Opening as draft not confident the current field subset provides sufficient debugging context
on failure. Looking for input before marking ready.

Changes

• Replace the chained .map(...).inspect_err(...).into_response() flow with an explicit match
• Extract Copy fields before moving order into add_order:
  from, sell_token, buy_token, kind, sell_amount, buy_amount
• Log extracted fields on error instead of the full OrderCreation struct
• Remove the unconditional order.clone()
• Preserve existing API behavior and response semantics

[github-actions]

This pull request has been marked as stale because it has been inactive a while. Please update this pull request or it will be automatically closed.