Let an early tap be a weak ball, and let the CPU put a sitter away

Step 4 (b), Oliver's pick. v372 measured why the ladder could not climb:
nearly every lost point was the player's own early whiff, the CPU barely
missed, and the auto-run reached everything, so no opponent dial decided
a point.

- The follow-through: a groundstroke swing meets a bounced ball up to
  60 ms after its window at q 0.05. The early whiff edge goes from ~70 ms
  back to ~130 ms, where the volley window had it before step 1.
- A sitter (a player ball under q 0.5) is put away with a chance that is
  the ladder (0.2 at the bottom of the Climb, 0.85 at the Champion, by
  difficulty in classic): clean, at the line, bounded by the rung's width.
- The player is on his heels for 0.5 s after a put-away of his own sitter.
  Without it the auto-run covered the whole court and no put-away won.
- Fixed a step-2 regression this surfaced: the drop's dig-out cap fired on
  every slice drive, so every low contact against the slicer was a sitter.

Measured at level 26: the Climb now slopes from 95% of points at the
Shambler to 28-39% at the Champion. The net rushers are still easier than
their neighbours. The log names put-aways. Three new tests; v373.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/state.js

@@ -7,7 +7,7 @@ import { gore } from './zombies.js'; // runtime-only cycle (zombies imports stat
 export const P = { x: 1.3, z: 22.8, side: 'P', pose: 'idle', poseT: 0, swingT: -1, facing: 1, runT: 0 };
 export const O = { x: -1.3, z: 1.0, side: 'O', pose: 'idle', poseT: 0, swingT: -1, facing: 1, runT: 0 };
 export const ball = { x: 0, y: 1, z: 20, vx: 0, vy: 0, vz: 0, g: 9.2,
-  active: false, lastHit: 'P', bounces: 0, rx: null, approach: null, spin: 1, soft: false, collected: false, kills: 0, bomb: false, flame: false,
+  active: false, lastHit: 'P', bounces: 0, rx: null, heels: 0, approach: null, spin: 1, soft: false, collected: false, kills: 0, bomb: false, flame: false,
   // NETPLAY: THE CALLED BALL PLAYS OUT. A verdict used to freeze the ball where it was — on the
   // striker's phone that is mid-roll, a whole court away from the call, and it read as the game
   // loop stopping. `scored` means "this flight is decided": physics keeps running, every scoring
@@ -206,7 +206,7 @@ export const other = s => s === 'P' ? 'O' : 'P';
 export const deuceSide = () => (score.pts[0] + score.pts[1]) % 2 === 0; // even points → deuce (right) side
 
 export function setupPoint() {
-  G.phase = 'pretoss'; ball.active = false; ball.bounces = 0; ball.scored = false; ball.rx = null; ball.approach = null;
+  G.phase = 'pretoss'; ball.active = false; ball.bounces = 0; ball.scored = false; ball.rx = null; ball.heels = 0; ball.approach = null;
   G.swingSnaps = null; G.rallyNear = null; G.swung = false;
   if (G.mode === 'splatter' && !G.match) { // always your serve, from wherever you're standing
                                            // (the MATCH falls through to the tennis branch below: