feat: LP token for Stableswap pool

[sivo4kin]

Fee Distribution System

On every deposit/withdraw, fees are auto-compounded:

1. Collect - Accrued swap fees collected from Core position
2. Protocol Cut - SWAP_PROTOCOL_FEE_X64 % deducted and sent to protocol's savedBalances
3. Compound - Remaining fees converted to liquidity and added to the position
4. Leftovers - Any fees that can't be paired (due to price imbalance) are stored as pendingFees and included in the next compound attempt

Result: LP token value grows over time as fees compound into liquidity. Protocol takes a fixed percentage; LPs keep the rest (including any temporarily unpairable amounts).

StableswapLPPositions Gas Report

Deployment: 3,548,031 gas / 16,605 bytes

Core Functions

Function	Min	Avg	Median	Max	Calls
deposit	24,840	186,765	148,989	281,540	3,477
withdraw	24,750	127,792	121,355	160,506	2,026
withdrawProtocolFees	25,090	56,786	51,191	99,674	4

View Functions

Function	Min	Avg	Median	Max	Calls
getProtocolFees	6,153	6,153	6,153	6,153	6
getPendingFees	6,224	6,224	6,224	6,224	3
totalSupply	807	2,800	2,807	2,807	291
totalLiquidity	763	2,761	2,763	2,763	1,830
SWAP_PROTOCOL_FEE_X64	506	506	506	506	3

ERC6909 Metadata

Function	Min	Avg	Median	Max	Calls
name	446	446	446	446	2
symbol	644	644	644	644	2
decimals	302	302	302	302	2

ERC6909 Token Operations

Function	Min	Avg	Median	Max	Calls
balanceOf	2,428	2,428	2,428	2,428	3,104
allowance	2,780	2,780	2,780	2,780	2
isOperator	2,910	2,910	2,910	2,910	4
approve	46,882	46,966	46,930	47,230	7
setOperator	24,114	40,548	46,026	46,026	4
transfer	23,770	23,898	23,950	23,950	7
transferFrom	24,690	24,810	24,840	24,870	10

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Always claim user fees even when no new Core fees

Because claimFees only calls claimFeesFor when claimed0 or claimed1 from Core collection is non‑zero, a user who has pending fees already accumulated in the LP token will get no payout if no new Core fees were collected in that call. This means claimFees silently does nothing in the common case where fees were accumulated earlier and the pool has since stopped accruing, despite the interface promising “claims accumulated fees for the caller.” Consider invoking claimFeesFor unconditionally (or based on pending fees) so users can claim existing balances even when Core returns zero.

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