add screenshot

Author: hjchen-circle

README.md

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 A sample application demonstrating how to build optimal USDC interoperability UX for wallets using Arc and Circle Gateway. This app showcases unified balance management, deposits, and cross-chain transfers across multiple EVM chains using Next.js and Supabase.
 
+<img width="830" height="658" alt="Interface for depositing to and transfering from a Gateway balance" src="public/screenshot.png" />
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 ## Prerequisites
 
 - Node.js 20.x or newer