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>

state.js

@@ -31,6 +31,9 @@ export const G = {
   splatT: 0,          // time survived in splatter mode — drives the difficulty ramp
   bombs: 0,           // bomb-ball stock (max TUNE.bombMax); the next serve auto-consumes one
   killMeter: 0,       // splatter kills toward the next bomb reward (every TUNE.bombEvery)
+  horde: null,        // active horde wave {t, spawnT, mgT} — machine-gun racket, no serving
+  splatGames: 0,      // splatter games you've won; the 2nd (and every one after) launches a horde
+  lastScoreT: -9,     // idleT of the last score voice — rate-limits umpire during a horde
   eatenT: 0,          // time since you were eaten — gates the restart tap
   missLog: [],        // swing diagnostics ring buffer (tennis mode) — inspect via T.G.missLog
   swingSnaps: null,   // ball-approach samples during the live swing, feeds the miss log