Stop the brute pulsing, and let a boss die where you can see it

The pulse was drawStatic being told a height instead of reading one. _slice.py
common-scales a sheet, so a crouched frame is genuinely shorter — 211 px against
its neighbours' 224 — and forcing every frame to the same on-screen height
stretched it back up, so the body swelled and shrank once per stride. Worst on
the brute because it is the biggest and slowest. The rule already existed for the
wound stages; it now applies to every frame, once, which also settles the
shamblers and the steward (their cycles vary by up to 9%).

A chapter boss now dies in its own beat instead of under the card announcing it:
the world drops to a third speed for 1.2 s, the screen kicks, a shockwave ring
blows out through 90 extra particles and six stains, and the CHAPTER DOWN card
holds off until the pieces have landed — about 1.4 s, measured.

Cards can hold off in general now (`wait`). First cut only delayed the card's
countdown while still drawing it, which is worse than no delay: caught it in a
screenshot before it shipped.

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

main.js

@@ -16,7 +16,10 @@ let last = performance.now();
 function frame(now) {
   requestAnimationFrame(frame); // schedule FIRST: one bad frame must never kill the loop (a thrown error froze the game for good)
   if (TUNE.fps && now - last < 1000 / TUNE.fps - 2) return; // frame cap (battery): skip RAF ticks until it's our beat
-  const dt = Math.min(0.04, (now - last) / 1000); last = now;
+  let dt = Math.min(0.04, (now - last) / 1000); last = now;
+  // A chapter boss dies in slow motion. The clock that ENDS it runs at real speed, so the effect is
+  // always the same length in seconds however far the world has been slowed.
+  if (G.slowT > 0) { G.slowT -= dt; dt *= TUNE.bossSlowMo; }
   update(dt); render();
 }