Splatter feel pass: melee, homing, multi-ball, clearer MG mode

From Oliver's feedback round:

- Racket melee: any swish (tap) in splatter cleaves shamblers within
  TUNE.meleeRange (1.7m) — a close-range survival tool. Works during a
  horde too (tap = swish only, still no serve). The racket-zombie boss
  (Phase 6, not built) is immune by design.
- Zombies home in on you: on YOUR half (z > netZ) they now drift toward
  P.x instead of walking a straight lane; far half stays an aimless
  shamble.
- Multi-ball / rapid fire: splatter is now a shooter — every tap/flick
  fires immediately (dropped the toss ritual there), and serving while a
  ball still flies stashes the old one into a new extraBalls array so it
  keeps arcing and killing (cap 6). Refactored the kill into a shared
  killZombie() with no ball coupling, used by ball hits, pellets, melee,
  and extra balls.
- Machine-gun mode clarity: confirmed free-walk (drag/arrows move you,
  auto-assist off) and tap-doesn't-serve during a horde; added a
  code-drawn "rambo" racket held forward with a muzzle flash over the
  player, and a splatter-specific serve prompt.

REVIEW on your phone — two opinionated calls, both easy to revert:
1. Dropped the toss in splatter (tap = instant quick-serve, pow 0.62).
   Rapid fire, but no apex-timing quality/pierce. Want the toss back as
   an option?
2. MG posture is a code-drawn forward racket, not a real body sprite —
   good enough, or worth a proper p_mg sprite later?
Also: each rapid serve still auto-consumes a stocked bomb, so bombs
deplete fast now — flag if that feels wrong.

Verified via window.T: melee kills a 1.0m zombie and spares a 4.5m one;
a near-half zombie drifts x 3→1.9 toward you; firing twice leaves 1
stashed ball + a fresh serve (barrage screenshot); extra balls kill and
pierce; free-walk during a horde (x 0→2.7); horde-tap melees without
serving; tennis toss-serve and Phase-4 bomb consume still work; 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, explode } from './zombies.js';
+import { updateZombies, spawnZombie, zombies, explode, meleeSwipe, stashExtraBall } from './zombies.js';
 
 // ------------------------------------------------------------- ballistics ----
 // Launch ball from (x0,y0,z0) so it lands at (tx, tz) with horizontal speed s under gravity g.
@@ -375,22 +375,20 @@ function trySwing(ch, isAI) {
 export function keyPressed(code) {
   if (code !== 'Space') return;
   audio(); // unlock on first gesture
-  if (G.horde) return; // horde: the racket auto-fires, taps do nothing — the thumb drag steers you
-  // splatter: a tap/flick during the brief 'over' beat arms the next serve immediately —
-  // reset inline, then fall through to pretoss so the finger is the only cadence limit
-  if (G.mode === 'splatter' && G.phase === 'over') { ball.active = false; setupPoint(); }
-  if (G.phase === 'pretoss' && score.server === 'P') {
-    if (G.mode === 'splatter') {
-      const flick = takeFlickAim();
-      if (flick) { // quick serve: no toss ritual, modest pace, aimed by the flick
-        ball.active = true; ball.collected = false; ball.bounces = 0; ball.firstLand = null;
-        ball.x = P.x + 0.35; ball.z = P.z; ball.y = 2.2; ball.g = TUNE.gravity;
-        hitServe(P, 0.62, flick);
-        return;
-      }
-    }
-    tossBall(P); return;
+  if (G.mode === 'splatter') {
+    // splatter is a shooter: every swish cleaves adjacent shamblers, and — outside a horde —
+    // fires a ball immediately. Serving while one still flies stashes it, so you can barrage.
+    meleeSwipe(P.x, P.z, TUNE.meleeRange);
+    if (G.horde) return;               // horde: MG auto-fires, the tap only swishes (no serve)
+    if (ball.active) stashExtraBall();  // keep the in-flight ball alive
+    const flick = takeFlickAim();       // flick aims; a plain tap auto-targets the nearest zombie
+    ball.active = true; ball.collected = false; ball.bounces = 0; ball.firstLand = null;
+    ball.x = P.x + 0.35; ball.z = P.z; ball.y = 2.2; ball.g = TUNE.gravity;
+    hitServe(P, 0.62, flick);
+    return;
   }
+  // tennis: the toss ritual + rally swing (unchanged)
+  if (G.phase === 'pretoss' && score.server === 'P') { tossBall(P); return; }
   if (G.phase === 'toss' && score.server === 'P') {
     // serve timing: distance from apex = quality
     const dy = Math.abs(ball.y - serveApexY());