MetaMask/metamask-extension ? reverse-engineered prompt

Build me a browser wallet extension like MetaMask that works in Chrome and Firefox and lets people connect to Ethereum sites, create or import a wallet, unlock it with a password, and manage their account from a small popup. I want the extension to show the wallet address, ETH and token balances, let me send crypto, and approve or reject connection requests from websites in a clear, easy to use way. It should also support the usual onboarding flow for a new user, with seed phrase backup and basic settings so people can switch networks and manage their security. Make it feel polished and reliable, with a clean interface that matches a modern browser extension. If you need to check current docs or browser extension guidance, look it up online and follow the latest best practices.