feat: Fix market price checker for market orders

[sunce86]

Problem

As a consequence of #2304, market orders
contain a bug, because their sell_amount doesn't contain the fee. This leads to market orders being classified as liquidity orders. https://github.com/cowprotocol/services/blob/main/crates/shared/src/order_validation.rs#L682

An order being classified as liquidity order might lead to order being less likely to be picked up by solvers? (Haris confirmed that only quasilabs can solve them as part of COW).

Example order: https://dev.explorer.cow.fi/orders/0xa1b886011c8d077187bead0e7d0ba1077f68de6bc0d6423b9ac643ead2153e33dd9eb88c5c6d2a85a08a96c7f0cccce27cb843cb65ae7f5a?tab=overview

[fleupold]

Can you explain orders are more often considered as out-of-market due to @2304. This is not intuitive to me (and makes it hard to understand if #2312 is the right fix)

[sunce86]

Before #2304, out of market order would require:

sell_amount/buy_amount < quote_sell/quote_buy.

So, if we increase quote_sell by adding fee_amount to it (as we did with #2304, making it quote_sell+quote_fee, then, right part of the equation is higher, which means more orders satisfy the equation and get marked as out of market.

[fleupold]

Wouldn't the right fix in this case be to compare

(sell_amount+fee_amount)/buy_amount < (quote_sell+quote_fee)/quote_buy

?

[sunce86]

sell_amount is a signed sell amount from order so it contains the fee already (it's a sell_amount_before_fee value).

[fleupold]

sell_amount is a signed sell amount from order so it contains the fee already (it's a sell_amount_before_fee value).

At least here (see below) we are using the raw orders sell amount, which (at least for market orders) doesn't contain the fee amount:

services/crates/autopilot/src/domain/fee/mod.rs

Lines 50 to 56 in d4fc3c2

	if boundary::is_order_outside_market_price(
	&order.data.sell_amount,
	&order.data.buy_amount,
	&quote.buy_amount,
	&quote.sell_amount,
	&quote.fee,
	) {