Phase 4: bomb balls

Ball boys deliver a bomb ball every TUNE.bombEvery (8) splatter kills, up
to TUNE.bombMax (3) in stock (G.bombs / G.killMeter in state). The next
serve auto-consumes one (hitServe, splatter-only) — no extra input, keeping
one-handed play. A bomb detonates on first zombie contact (regardless of
pace) or, if it misses everyone, on its first bounce: explode() splatters
everything within TUNE.bombRadius (2.5m), each kill feeding ball.kills so
the Phase-2 fanfare escalates naturally, and leaves a crater — big stain,
size-3 pile, 40 particles, 0.1s hitstop, boom(). New synth boom() in
audio.js. Bomb ball renders black with a flickering orange fuse; the HUD
shows stocked bombs as black/orange pips by the YOU line. Both explode
sites set phase='over' so the serve loop doesn't stall on the killed ball.

Alternative delivery ideas Oliver floated but not built: umpire throws it,
or court pickup.

Verified via window.T: 8th kill earns a bomb (meter resets); a serve
consumes one and renders #111 black + orange fuse; a pow-0 bomb amid 4
clustered zombies kills all 4 with 'MASSACRE ×4', boom, hitstop 0.1,
crater stain (r1.4) + size-4 pile; a bomb that misses still craters on
first bounce; bombs never leak into tennis (mode guard); 3 HUD pips; no
console errors.

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

gameplay.js

@@ -4,7 +4,7 @@ import { TUNE, COURT, CONTACT, VOLLEY, ZONE_DEPTH, HOME, P_BOUNDS, TOSS, SHOT_DE
 import { P, O, ball, score, crowd, G, other, deuceSide, setupPoint, sendBoy } from './state.js';
 import { audio, pock, swish, applause, voice } from './audio.js';
 import { axisX, axisZ, takeFlickAim } from './input.js';
-import { updateZombies, spawnZombie, zombies } from './zombies.js';
+import { updateZombies, spawnZombie, zombies, explode } from './zombies.js';
 
 // ------------------------------------------------------------- ballistics ----
 // Launch ball from (x0,y0,z0) so it lands at (tx, tz) with horizontal speed s under gravity g.
@@ -79,6 +79,7 @@ function doHit(ch, quality, aim) {
   G.wasServe = false; // a serve volleyed back pre-bounce must not fault-check the return
   ball.pow = quality; // carried pace: zombies splatter only above zSplatQ
   ball.kills = 0;     // fresh shot: multi-kill streak restarts
+  ball.bomb = false;  // only a bomb-consuming serve is a bomb; any other hit clears it
   if (ch.side === 'P') { // shot marker: where this will land — red means it's going out
     const ok = G.mode !== 'tennis' || (Math.abs(tx) <= COURT.W / 2 + 0.02 && tz >= -0.02 && tz <= COURT.netZ);
     G.outMarker = { x: tx, z: tz, out: !ok, t: 1.3 };
@@ -120,6 +121,8 @@ function hitServe(sv, quality, aim = null) {
   ball.lastHit = sv.side; ball.bounces = 0;
   ball.pow = quality;
   ball.kills = 0;     // fresh serve: multi-kill streak restarts
+  ball.bomb = G.mode === 'splatter' && G.bombs > 0; // auto-consume a stocked bomb ball
+  if (ball.bomb) G.bombs--;
   if (sv.side === 'P') G.outMarker = { x: boxX, z: tzs, out: G.mode === 'tennis' && !inServeBox(boxX, tzs), t: 1.3 };
   G.phase = 'rally'; pock(1, 1100);
   sv.pose = 'serve'; sv.poseT = 0;
@@ -229,6 +232,10 @@ export function inServeBox(x, z) {
 function onBounce() {
   ball.bounces++;
   pock(0.35, 500);
+  if (G.mode === 'splatter' && ball.bomb && ball.bounces === 1) { // a bomb that missed everyone still blows up
+    explode(ball.x, ball.z); ball.active = false; ball.bomb = false;
+    G.phase = 'over'; G.overT = TUNE.splatterOverT; return;
+  }
   if (G.mode !== 'tennis') return; // no lines, no faults — the umpire has other concerns
   if (ball.bounces === 1) {
     ball.firstLand = { x: ball.x, z: ball.z };