Re-slice corrected bounce sheet; ball under the hand; stable landing rings

- p_bounce/p_bounce2 re-extracted from Oliver's corrected _sheet_pbounce.png
  (racket properly in the right hand)
- bounce ball offset 0.4 -> 0.32 so it sits under the reaching hand
- landing rings draw with integer-snapped center/radii and a solid 2px
  stroke — the sub-pixel anti-aliasing shimmer read as flickering

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

game.js

@@ -623,8 +623,11 @@ function drawBoy(b) {
 }
 function drawRing(x, z, color) {
   const p = proj(x, 0, z);
-  ctx.strokeStyle = color; ctx.lineWidth = 1.2;
-  ctx.beginPath(); ctx.ellipse(p.x, p.y, p.s * 0.3, p.s * 0.12, 0, 0, 7); ctx.stroke();
+  // integer-snapped so the moving ring steps whole pixels instead of shimmering
+  const cx = Math.round(p.x), cy = Math.round(p.y);
+  const rx = Math.max(2, Math.round(p.s * 0.3)), ry = Math.max(1, Math.round(p.s * 0.12));
+  ctx.strokeStyle = color; ctx.lineWidth = 2;
+  ctx.beginPath(); ctx.ellipse(cx, cy, rx, ry, 0, 0, 7); ctx.stroke();
 }
 
 function drawChar(ch) {
@@ -733,7 +736,7 @@ function render() {
   // server idly bouncing the ball while waiting
   if (phase === 'pretoss') {
     const sv = score.server === 'P' ? P : O;
-    const bx = sv.x - 0.4 * (sv.side === 'P' ? 1 : -1), by = Math.abs(Math.sin(idleT * 3.6)) * 0.78; // floor to hand
+    const bx = sv.x - 0.32 * (sv.side === 'P' ? 1 : -1), by = Math.abs(Math.sin(idleT * 3.6)) * 0.78; // floor to the reaching hand
     const sh = proj(bx, 0, sv.z);
     ctx.fillStyle = 'rgba(0,0,0,0.3)';
     ctx.beginPath(); ctx.ellipse(sh.x, sh.y, Math.max(1.5, sh.s * 0.08), Math.max(1, sh.s * 0.035), 0, 0, 7); ctx.fill();