Phase 5: horde waves + machine-gun racket

Winning your 2nd splatter game (G.splatGames) — or triple-tapping the
umpire in splatter (forceZombies now calls startHorde) — launches a 12s
horde (TUNE.hordeLen). During a horde: the match ball is gone and taps do
nothing; the racket auto-fires pellets straight up-court at TUNE.mgRate
(6/s, ±4° spread, 26 m/s, flat, 1.2s life) and the thumb DRAG steers you
(auto-assist disabled). Zombies pour in at TUNE.hordeRate (2.5/s) from the
far baseline and the sides, ignoring zMax; the speed ramp still applies.

Pellets live in a new zombies.js `pellets` array, kill on contact (always
splatter-quality). splatter() gains a fanfare flag — pellet kills make
gore/piles/points but skip the multi-kill streak so a horde doesn't spam
MASSACRE. splatPoint() gains a quiet flag: during a horde the umpire only
calls a score every >2s (game-win lines always speak); the HUD score keeps
ticking. Horde ends → setupPoint() resumes serving, voice('quiet_dark');
leftover zombies stay for you to mop up. Eaten stays lethal during hordes
(a zombie reaching you ends it and clears the swarm). Pellets render as
2×2 yellow tracers with a ground shadow; serve prompt suppressed while
G.horde. window.T exposes pellets + forceZombies.

NOTE for Oliver: per spec every game won after the 2nd triggers a horde,
and games won by the machine gun mid-horde count too, so play gets very
horde-heavy after game 2 — flag if you want a cooldown or a knob.

Verified via window.T: cheat + 2nd-game both launch the horde (1st does
not); ~29 spawns over exactly 12s; pellets stream (7 in flight) and clear
a lane, building piles/gore; 4 points scored but the umpire speaks once
(rate-limited); horde ends cleanly back to pretoss; eaten still fires
mid-horde; regression ladder green — tennis 11/12, Phase 1 flick-serve,
Phase 2 DOUBLE→TRIPLE, Phase 4 MASSACRE ×4; no console errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

config.js

@@ -27,6 +27,9 @@ export const TUNE = {
   bombEvery: 8,     // splatter kills between bomb-ball rewards
   bombMax: 3,       // bomb balls you can stock at once
   bombRadius: 2.5,  // m blast radius of a bomb ball
+  hordeLen: 12,     // s a horde wave lasts
+  hordeRate: 2.5,   // zombies spawned per second during a horde
+  mgRate: 6,        // machine-gun pellets fired per second during a horde
   missHud: 1,       // show the last miss reason on screen (full log: T.G.missLog)
 };