Sir-MmD/vpn-ui ? reverse-engineered prompt

Build me an enhanced VPN management panel like 3X UI, but with a cleaner interface and support for a lot more protocols in one place.

I want admins to be able to create and manage accounts, inbounds, traffic limits, device limits, expiry dates, and online status, then generate and export client links in TXT and PDF. The panel should support common VPN and proxy options like OpenVPN, L2TP, PPTP, SSTP, IKEv2, WireGuard, AmneziaWG, OpenConnect, MTProto, SSH, GRE, and the Xray based protocols already mentioned in the project. It should also include multi admin access, reseller style accounts with traffic balances, bulk actions for users and inbounds, freezing accounts, and client to client access when needed.

Make it easy to install on Linux servers, include automatic certificate handling, and keep everything working after renewals without disconnecting users. If you need to, look up the latest docs online so the setup and protocol support are correct.