Sweep the dead code off the court

EATEN_GRAB (write-only marker), ball.firstLand (written five places, read
nowhere), zombies' unused VOLLEY import, three scoreboard palette fields
from the pre-PNG board, the x_tin.png nothing references, and a dozen
export keywords on functions no module ever imported.

Kept on purpose: o_run3/o_run4.png — the SPR list excludes them so both
tours run on two frames (the women's set has no 3/4 twins), per the comment
at the preload list.

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

gameplay.js

@@ -29,11 +29,11 @@ export function predictLanding() { // first-bounce point, closed form — exact,
 // further, which is the whole fix: a shambler at the far baseline costs the same short pull as
 // one on top of you, so the gesture always fits on the screen. The first body standing in the
 // lane is the target; the cone widens with range so distant lanes stay pickable.
-export const pullFrac = mag => Math.max(0, Math.min(1, (mag - TUNE.pullMin) / (TUNE.pullFull - TUNE.pullMin)));
+const pullFrac = mag => Math.max(0, Math.min(1, (mag - TUNE.pullMin) / (TUNE.pullFull - TUNE.pullMin)));
 export const pullQuality = mag => TUNE.pullQMin + pullFrac(mag) * (1 - TUNE.pullQMin);
 // pullQuality inverted: hitServe is handed a quality, not a drag, and the band it leaves behind is
 // drawn at the same weight the live preview had.
-export const qualityFrac = q => Math.max(0, Math.min(1, (q - TUNE.pullQMin) / (1 - TUNE.pullQMin)));
+const qualityFrac = q => Math.max(0, Math.min(1, (q - TUNE.pullQMin) / (1 - TUNE.pullQMin)));
 // A pull that STOPS in the band at the top of the draw, rather than merely reaching it. See
 // TUNE.perfectBand for why the old "quality == 1" test praised almost every serve.
 export const pullPerfect = mag => mag >= TUNE.pullFull && mag <= TUNE.pullFull * TUNE.perfectBand;
@@ -139,7 +139,7 @@ function doHit(ch, quality, aim) {
   }
   ball.g = g;
   ball.vx = v.vx; ball.vy = v.vy; ball.vz = v.vz;
-  ball.lastHit = ch.side; ball.bounces = 0; ball.firstLand = null;
+  ball.lastHit = ch.side; ball.bounces = 0;
   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
@@ -162,7 +162,7 @@ function doHit(ch, quality, aim) {
 
 // ----------------------------------------------------------------- serve ----
 function tossBall(sv) {
-  ball.active = true; ball.bounces = 0; ball.firstLand = null; ball.collected = false;
+  ball.active = true; ball.bounces = 0; ball.collected = false;
   // The player is right-handed: he tosses with his LEFT hand (viewer's left) and hits with the
   // racket on the viewer's right, so the ball goes up almost over his head — a big offset either way
   // lands it on the wrong side of one of those two frames. The opponent is drawn from the front and
@@ -171,7 +171,7 @@ function tossBall(sv) {
   ball.vx = 0; ball.vz = 0; ball.vy = TOSS.vy; ball.g = TUNE.gravity;
   G.phase = 'toss';
 }
-export function serveApexY() { return TOSS.y0 + TOSS.vy * TOSS.vy / (2 * TUNE.gravity); } // ~2.95
+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).
@@ -522,10 +522,10 @@ function startChangeover() {
 // that ("[0,1,2,3,4].find(...)"), so the moment the rack grew past five, a burst weapon sitting in
 // slot 5..9 could never be found and never spent: beacon, flamer and rocket sat at their pickup
 // count forever. One accessor, one place that knows the range.
-export const slotEntry = i => (i === 0 ? G.temp : G.rack[i - 1]) || null;
+const slotEntry = i => (i === 0 ? G.temp : G.rack[i - 1]) || null;
 export const slotId = i => slotEntry(i)?.id || (i === 0 ? 'ball' : null);
 export const slotStock = i => { const e = slotEntry(i); return e ? e.n : (i === 0 ? Infinity : 0); };
-export const slotOf = id => { // -1 if you are not carrying it
+const slotOf = id => { // -1 if you are not carrying it
   for (let i = 0; i <= RACK_MAX; i++) if (slotId(i) === id) return i;
   return -1;
 };
@@ -549,7 +549,7 @@ export function grantWeapon(id, n = WEAPONS[id].tin) {
 
 // Spend one from a slot, and hand you back plain balls when it runs dry. The temp weapon does not
 // leave an empty dimmed slot behind the way a rack entry does — slot 0 simply becomes BALL again.
-export function spendSlot(i) {
+function spendSlot(i) {
   const e = slotEntry(i);
   if (!e) return;
   if (--e.n > 0) return;
@@ -646,7 +646,7 @@ function stockTestRack() {
     else if (G.rack.length < RACK_MAX) G.rack.push({ id, n: WEAPONS[id].tin });
   }
 }
-export function tickTestMode(dt) {
+function tickTestMode(dt) {
   if (!G.testMode) return;
   stockTestRack();   // no barrels: the rack is already full of everything they would hand you, and
 }                    // one rolling across the sandbox was just something else to look at
@@ -934,7 +934,6 @@ function onBounce() {
   }
   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 };
     const wasServe = G.wasServe; G.wasServe = false;
     if (wasServe) {
       if (!inServeBox(ball.x, ball.z)) { ball.active = false; fault(); }
@@ -1156,7 +1155,7 @@ export function dragServe(aim) {
   // walked the player around between shots was the confusing part, not the fire rate.
   if (ball.active && G.phase !== 'toss') // the old ball flies on as a ballistic clone
     extras.push({ x: ball.x, y: ball.y, z: ball.z, vx: ball.vx, vy: ball.vy, vz: ball.vz, pow: ball.pow || 0.5, t: 2.5, g: ball.g, wid: ball.wid });
-  ball.active = true; ball.collected = false; ball.bounces = 0; ball.firstLand = null;
+  ball.active = true; ball.collected = false; ball.bounces = 0;
   ball.x = P.x + 0.12; ball.z = P.z; ball.y = 2.2; ball.g = TUNE.gravity; // over his head, see tossBall
   // a full pull is quality 1.0, but only a pull that STOPS at the top of the draw is praised
   hitServe(P, pullQuality(aim.mag), aim, pullPerfect(aim.mag));