[BIP-868] Enable EURe/USDC gauge on Arbitrum (uncapped)

Summary:

Add a veBAL Gauge for the EURe, USDC pool on Arbitrum:

https://balancer.fi/pools/arbitrum/v3/0xa978cc348a0b5de8bd564a1d8fe437787fd12664.

Tokens, EURe 0x0c06ccF38114ddfC35E07427B9424AdcCa9F44F8, USDC 0xaf88d065e77c8cC2239327C5EDb3A432268e5831.

References/Useful links:

• Website: https://monerium.com/ • Documentation: https://monerium.dev/docs/welcome • Github Page: https://github.com/monerium/ • Discord: https://monerium.com/invite/discord • X: https://x.com/monerium * Dune: https://dune.com/monerium/monerium-eure

Protocol Description:

Assets

• EURe, regulated euro e-money token issued by Monerium, 1,1 backed by high quality liquid assets, redeemable to bank accounts, audited contracts, multi-sig governed. Contract, 0x0c06…F44F8 on Arbitrum.

• USDC, native USDC on Arbitrum. Contract, 0xaf88…e5831.

Protocols

• Monerium EURe, fiat on-off-ramp, authorized Electronic Money Institution licensed to operate in the EEA, UK, and Switzerland. Contracts audited by Ackee. 30k token holders and €6 billion in volume.

• Balancer v3, stableswap pool on Arbitrum.

Historic prices, source of highest liquidity

• EURe is redeemable 1 to 1 to EUR according to emoney law on monerium.app.

• Coingecko: https://www.coingecko.com/en/coins/monerium-eur-money

• Coinmarketcap: https://coinmarketcap.com/currencies/monerium/

• USDC, native Arbitrum USDC maintains 1.00 USD.

Motivation:

Establish deep EUR,USD on-chain FX liquidity on Arbitrum using a MiCA-compliant euro e-money token, EURe. This reduces slippage for EUR cross-margining and payments while routing volume through Balancer.

Specifications:

1. Governance: EEURe on Arbitrum is upgradeable by an owner multi-sig at 0xD4d43A82708261F2995f7Ba65319d8664B992A96, set to 3 of 6 signatures; the owner manages role-based access with two roles, admins and system accounts. Admins set and adjust mint allowances for each system account, and system accounts can mint and burn only within their current allowance. Each mint reduces that account’s remaining allowance by the minted amount, which prevents a compromised system account from minting above its limit. Admins continuously monitor allowances, and reconciliation runs several times per day to spot anomalies and reset limits as needed.
2. Oracles: Monerium is working with Chainlink to create an oracle for EURe. EURe issuance and redemption does not rely on external price oracles
3. Audits: smart contracts are audited by Ackee, https://github.com/monerium/smart-contracts/blob/main/audits/v2.0.0-ackee-blockchain-monerium-smart-contracts-report-1.2.pdf
4. Centralization vectors: Issuer controls, EURe is fiat-backed e-money, Monerium can mint, burn, and manage mint allowances via multi-sig. Contracts are upgradeable. These are disclosed and audited. Front-end hosting is centralized.
5. Market History: EURe is designed to track EUR 1 to 1, subject to normal EUR,USD FX moves versus USD. Fiat issuance and redemption govern supply. There has been no major volatility or depeg since Monerium was founded.
6. Value: This pool is intended to be the primary EURe,USDC liquidity venue on Arbitrum. It creates a clean EUR,USD on-chain FX rail for applications, traders, treasuries, and payments.

Technical Specification

The Balancer Maxi LM Multisig 0xc38c5f97B34E175FFd35407fc91a937300E33860 will interact with the GaugeAdderv4 at 0x5DbAd78818D4c8958EfF2d5b95b28385A22113Cd and call the addGauge function with the following arguments: gauge(address):0x7f49d37d0da53a4899bc0ba916f59ec9d4e6d1e2 gaugeType(string): Arbitrum