v1.12 — Watch tactical-computer feed on every Mac

Fix: the Apple Watch / iPhone "tactical computer" companion now works fleet-wide

Previously only the imac-g5 and mini-intel per-machine cfgs armed the watchlink
feed, so the companion HUD received no data on the G3, the G4s, or any Mac
whose model isn't in the per-machine map — watch_host stayed at its off
default ("").

This release puts Bonjour auto-discovery (watch_host "auto") in all four
per-arch baselines (ppc750=G3, ppc7400=G4, ppc970=G5, x86_64=Intel). Per
host.c the per-arch cfg runs after config.cfg and the per-machine overlay
leaves watch_host untouched, so this covers every Mac of each arch —
including models not in the machine map — with a single knob. The wrist now
"just works" on any supported Mac with no console command. Discovery is
time-bounded (~30 s) and inert during demos, so a phoneless game costs nothing.

No engine code changed — the binary is byte-for-byte identical to v1.11; only
the staged config differs. DMG built and content-verified on Tiger (mini-g4).

Companion app: https://github.com/matthewdeaves/quake2-tactical-watch