do_complete_payment() does not transfer any tokens despite its name

[SYLVIANNORUKA]

Description
do_complete_payment() is documented as "Complete a payment with a risk assessment," but its implementation is a single line -- Self::get_effective_fee_for_payment(...) -- that performs no token transfer and mutates no state; it is purely a fee-preview calculation identical in effect to calling get_effective_fee_for_payment() directly. An integrator reading the function name and doc comment in isolation could reasonably believe calling it actually moves funds, when it does not.

Affected modules: contracts/hamplard/src/lib.rs

A function named and documented as completing a payment performs no payment at all.

Expected Behavior
Either rename do_complete_payment() to reflect that it is a read-only fee preview (and consider removing it as a duplicate of get_effective_fee_for_payment()), or update its doc comment to explicitly clarify it performs no transfer.

Tasks

Rename do_complete_payment() (or remove it in favor of get_effective_fee_for_payment()) to avoid implying it moves funds.

Update the doc comment to accurately describe its behavior if the function is kept.

Grep the backend/SDK integration code for any usage that assumes it performs a transfer.

[testersweb]

Wanted to take this one. A function named do_complete_payment that quietly returns a fee preview without touching state is the kind of mismatch that causes real integration bugs downstream. I'll rename or remove it, fix the doc comment, and grep the SDK and backend integration code for any caller that assumes a transfer happened. Happy to start once assigned.