tmorgansl/openvpn-notifier — reverse-engineered prompt

Build me a small command line tool that watches an OpenVPN server and sends a Pushover notification when someone connects or disconnects.

It should connect to the OpenVPN management port, defaulting to localhost on port 5555, and check every few seconds for client changes. I want to pass in my Pushover app token and user key when I start it, and it should have a simple help command that explains the available options.

Keep it lightweight and suitable for a home server or Raspberry Pi with just a few VPN users. It should avoid sending multiple Pushover requests at the exact same time, and the messages should clearly say whether a client connected or disconnected. Please make it easy to build from source with Rust and Cargo, and include basic README instructions for installing, running, and the OpenVPN UDP disconnect note about explicit exit notify.