Weapons: a courtside rack you pick from + pixel-art HUD

Tins now accumulate on a courtside rack (cap 3) instead of replacing each other; a PLAIN slot banks specials for later, and GUN is a charge you pop for an auto-fire burst. Tap the rack or press 1-5 to choose what your serve throws. A fresh delivery auto-equips but never overrides a deliberate PLAIN, and the 1:1 sudden-death duel forces plain balls.

HUD gets real art: generated pixel-art weapon icons, an ornate Wimbledon scoreboard PNG backing the live text (no more code-drawn boxes on top), and a bundled Silkscreen pixel font replacing the system serif. Rack tiles get padding, count-over-label alignment, and an infinity marker on the ball.

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

config.js

@@ -35,6 +35,8 @@ export const TUNE = {
   ballChangeFirst: 3, // game of the first new-balls delivery (real rule: 7, then every 9 — too sparse here)
   ballChangeEvery: 4, // games between deliveries after the first
   bombMax: 3,       // bomb balls in a fresh tin
+  wCap: 3,          // per-type cap on the courtside rack — tins accumulate, but only so many
+  rackH: 22,        // px height of the bottom weapon rack (feel knob: how much court it covers)
   bombRadius: 2.5,  // m blast radius of a bomb ball
   hordeLen: 12,     // s a horde wave lasts
   hordeRate: 2.5,   // zombies spawned per second during a horde