Build 1 (49f02c9)

feat: fake disconnect, godmode and noclip while vanished

Hiding the entity removes a player from the world, but a client that
loses an entity says nothing about it and no server side handler runs.

The module gains vanishevent.Fire, which raises an engine game event from
Lua: a real player_disconnect on vanish makes every client print the leave
message and run its own disconnect path, and player_connect on unvanish
makes the return read as a rejoin. Server side, a configurable selection of
PlayerDisconnected handlers is run so admin mods log the departure.

A vanished player also gets godmode, noclip, notarget and pass-through
collisions, restored from the state captured when they vanished.