Generated idle/serve animation sprites; assist runs at full speed with animation

- new 5-pose sheets per character: idle weight-shift x2, ball-bounce crouch,
  serve trophy pose (toss), overhead smash
- serve shows toss stance through the ball toss, smash frame on contact
- auto-assist: full player speed, adds depth tracking after the bounce,
  and drives the run animation + facing like manual movement

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

game.js

@@ -18,7 +18,7 @@ const TUNE = {
   aimError: 2.4,           // m of scatter at quality 0
   perfectMs: 45,           // |offset from window center| for PERFECT
   aiQualityMin: 0.55, aiQualityMax: 0.95, aiFlub: 0.05,
-  autoAssist: matchMedia('(pointer: coarse)').matches ? 0.65 : 0, // auto-run toward ball x (mobile)
+  autoAssist: matchMedia('(pointer: coarse)').matches ? 1.0 : 0, // auto-run toward the ball (mobile)
 };
 
 const COURT = { L: 23.77, W: 8.23, netZ: 11.885, netH: 0.914, netW: 10.06, serviceD: 6.4 };
@@ -162,8 +162,8 @@ function say(text, delay = 0) { // ponytail: speechSynthesis umpire; swap for re
 // ---------------------------------------------------------------- sprites ----
 // assets/<name>.png; game falls back to code-drawn figures until sprites load.
 const SPR = {};
-for (const n of ['p_idle','p_run1','p_run2','p_swing1','p_swing2','p_serve',
-                 'o_idle','o_run1','o_run2','o_swing1','o_swing2','o_serve']) {
+for (const n of ['p_idle1','p_idle2','p_bounce','p_toss','p_smash','p_run1','p_run2','p_swing1','p_swing2',
+                 'o_idle1','o_idle2','o_bounce','o_toss','o_smash','o_run1','o_run2','o_swing1','o_swing2']) {
   const img = new Image();
   img.onload = () => SPR[n] = img;
   img.src = 'assets/' + n + '.png';
@@ -396,15 +396,24 @@ function update(dt) {
     if (phase === 'rally') {
       P.x += mx * TUNE.playerSpeed * slow * dt;
       P.z += mz * TUNE.playerSpeed * slow * dt;
+      let assist = 0;
       if (!mx && !mz && TUNE.autoAssist > 0 && ball.active && ball.lastHit === 'O') {
-        const d = ball.x - P.x; // drift toward the incoming ball so one thumb suffices
-        P.x += Math.sign(d) * Math.min(Math.abs(d), TUNE.playerSpeed * TUNE.autoAssist * slow * dt);
+        const rate = TUNE.playerSpeed * TUNE.autoAssist * slow * dt;
+        const dx = ball.x - P.x; // run toward the incoming ball so one thumb suffices
+        assist = Math.sign(dx) * Math.min(Math.abs(dx), rate);
+        P.x += assist;
+        if (ball.bounces > 0) { // ball on our side: also close the depth gap
+          const dz = Math.max(COURT.netZ + 1.5, Math.min(24.5, ball.z)) - P.z;
+          P.z += Math.sign(dz) * Math.min(Math.abs(dz), rate);
+          if (!assist) assist = dz;
+        }
       }
       P.x = Math.max(-6.5, Math.min(6.5, P.x));
       P.z = Math.max(COURT.netZ + 1.2, Math.min(26, P.z));
-      P.runT += (Math.abs(mx) + Math.abs(mz)) * dt;
-      if (P.pose !== 'swing' && P.pose !== 'serve') P.pose = (mx || mz) ? 'run' : 'idle';
-      if (mx) P.facing = mx > 0 ? 1 : -1;
+      const moving = mx || mz || Math.abs(assist) > 0.005;
+      P.runT += moving ? dt : 0;
+      if (P.pose !== 'swing' && P.pose !== 'serve') P.pose = moving ? 'run' : 'idle';
+      if (mx || assist) P.facing = (mx || assist) > 0 ? 1 : -1;
     }
   }
   if (P.swingT >= 0) { P.swingT += dt; trySwing(P, false); if (P.swingT > 0.4) P.swingT = -1; }
@@ -492,11 +501,13 @@ function drawChar(ch) {
   const hpx = 1.88 * p.s;
   // pick sprite
   const pre = ch.side === 'P' ? 'p_' : 'o_';
-  let name = pre + 'idle';
+  let name = pre + (Math.floor(idleT * 1.6) % 2 ? 'idle1' : 'idle2'); // idle weight shift
+  if (phase === 'pretoss' && ch.side === score.server && ch.pose === 'idle')
+    name = pre + (Math.abs(Math.sin(idleT * 3.6)) < 0.5 ? 'bounce' : 'idle1'); // crouch as the ball drops
   if (ch.pose === 'run') name = pre + (Math.floor(ch.runT * 9) % 2 ? 'run1' : 'run2');
   if (receiverWaiting) name = pre + (sway > 0 ? 'run1' : 'run2'); // split-step shuffle
   if (ch.pose === 'swing') name = pre + (ch.poseT < 0.15 ? 'swing1' : 'swing2');
-  if (ch.pose === 'serve') name = pre + 'serve';
+  if (ch.pose === 'serve') name = pre + (phase === 'toss' ? 'toss' : 'smash');
   if (ch.pose === 'run') p.y -= Math.floor(ch.runT * 18) % 2; // 1px run bob
   const img = SPR[name];
   // shadow