MANUAL RUN: git-recon battles: feel lag compensation and replay on a real LAN #1215

Follow-up to #1181 / #1214. Those add lag-compensated hits (up to MAX_REWIND = 0.3 s back) and input replay for your own soldier. Tests cover them, but #1181 asked for a real LAN check, which needs two machines and a person playing.

1. Host a battle on one machine and join from another on the LAN (ffa).
2. Strafe hard left and right: your soldier shouldn't rubber-band.
3. Shoot a strafing opponent at range, aiming at where you see them. Hits should land without leading.
4. Watch for "shot behind cover": a hit that lands after the target already ducked behind a file. It can happen by up to the shooter's lag. If it feels bad, lower MAX_REWIND in apps/git-recon/src/sim/game.ts.