Zombie tennis: one game per opponent, blood only

Triage failed the only test that matters — "i think the normal player does
not grasp this" — and the lesson across four drill designs is that every
invented rule needs teaching, while the rules the scene already implies need
none. So the new mode is the game's own oldest rule: tennis.

MATCH TEST in the back room (#match). One game per opponent, real 15/30/40
scoring. Built on top of the duel machinery: G.match runs a permanent
interlude, which is already what makes serving tennis-like, hides the rack,
quiets the spawn director and wakes racketAI. The one change is in
resolveInterlude — a settled point feeds matchPoint instead of ending
anything. About 90 lines for a whole mode, because the deepest system in the
repo was already built.

The score is the body: a quarter of its pool per point won, floored at 1, so
a love game walks the racket zombie through every wound stage and the game
point fells it. Its points draw your blood — hp--, eaten at zero, matchHeal 2
per game won is how you last. Regicide is inherited: kill the body mid-game
and the game banks by hand.

The timing is drawn, per Oliver's ask: an approach ring around the incoming
ball that kisses a fixed inner ring exactly at the sweet contact distance
(gold inside the band), and an apex band beside the toss spanning the same
0.12m keyPressed scores as perfect, with a tick riding the live ball. Both
cues use the mechanics' own numbers, so the picture cannot lie.

Verified by autopilot: 7 games in 90 simulated seconds, opponents 1..8, pools
4/6/8/10, wounds tracking points exactly.

36 tests, 15 seeds clean.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/gameplay.js

@@ -194,7 +194,7 @@ function tossBall(sv) {
   ball.vx = 0; ball.vz = 0; ball.vy = TOSS.vy; ball.g = TUNE.gravity;
   G.phase = 'toss';
 }
-function serveApexY() { return TOSS.y0 + TOSS.vy * TOSS.vy / (2 * TUNE.gravity); } // ~2.95
+export function serveApexY() { return TOSS.y0 + TOSS.vy * TOSS.vy / (2 * TUNE.gravity); } // ~2.95
 
 // how many 10%-pace cuts a shot may take to get over the net. 8 wasn't enough for a target
 // sitting right behind the tape — that needs a near-vertical drop, so ~10 cuts (pace × 0.35).
@@ -379,7 +379,7 @@ function hitServe(sv, quality, aim = null, perfect = quality > 0.999) {
 }
 
 // ---------------------------------------------------------------- scoring ----
-function scoreKey() {
+export function scoreKey() {
   const N = ['love', 'fifteen', 'thirty', 'forty'];
   const s = score.server === 'P' ? [score.pts[0], score.pts[1]] : [score.pts[1], score.pts[0]];
   if (s[0] >= 3 && s[1] >= 3) {
@@ -432,7 +432,7 @@ export function cheer(seconds, vol) {
   crowd.cheer = Math.max(crowd.cheer, seconds, APPLAUSE_T);
 }
 
-function advancePoint(side) { // shared scoring math; returns whether a game was won
+export function advancePoint(side) { // shared scoring math; returns whether a game was won
   const i = side === 'P' ? 0 : 1, j = 1 - i;
   score.pts[i]++;
   if (score.pts[i] >= 4 && score.pts[i] - score.pts[j] >= 2) {