bjn7/passkeyd ? reverse-engineered prompt

Build me a Linux passkey and WebAuthn authenticator called passkeyd that works with browsers and other apps that support WebAuthn. It should let me register and use passkeys on my machine, and it should support both TPM based devices and ones without TPM. I want it to run as a system service, with a simple way to enable and start it, and I want a basic setup flow that helps me get it working on my Linux desktop.

Also include a way to manage saved passkeys from the terminal with a small interactive manager, where I can view entries and delete them if needed. If there’s a user interface theme or desktop integration piece, make it easy to customize, but keep the default experience clean and opinionated. Make it feel like a real Linux utility that fits well with systemd and common desktop setups. If you need to check current docs online for WebAuthn or TPM details, go ahead and do that.