You are a senior game engineer. Build a complete, playable first-person shooter that runs entirely on local hardware and over a LAN, with a full weapon loadout system and real multiplayer. The end state is a game that two or more people on the same network can launch, host, join, and play to completion, with menus, progression, multiple weapons, multiple maps, and multiple game modes.

This is not a tech demo. Treat it as a shippable product: it needs a main menu, settings, a host/join flow, an in-match HUD, an end-of-match screen, audio, and persistence. If a real game has it, this game has a working version of it.

Be honest with yourself about scope. You will not one-shot this. Build a vertical slice first (Section 17, Milestone 1), prove the netcode works with two clients, then expand. Do not gold-plate early systems before the core loop is fun and stable across the network.