v2.4.2 — Watch tactical-computer feed on every Mac

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

Previously only the iMac G5 shipped with the watchlink feed armed, so the
companion HUD received no data on the G3, the G4s, and the Intel boxes —
the per-machine bundle cfgs for those machines never set watch_host, so the
feature stayed off (its archived default is "").

This release adds Bonjour auto-discovery (watch_host "auto") to every
per-machine cfg (yosemite/G3, sawtooth, quicksilver, mini-g4, mini-intel,
imac-2019), matching the G5. The wrist now "just works" on any supported Mac
with no console command. Discovery is time-bounded (~30 s) and fully inert
during timedemo/bench, so a phoneless game still costs nothing.

No engine code changed — the binary is byte-for-byte identical to v2.4.1; only
the staged per-machine config differs. DMG built and content-verified on Tiger
(mini-g4); the four-slice fat binary + all per-machine cfgs were md5-checked
inside the image against source.

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