Miss log: every tennis swing logs why it failed, last reason shown on HUD

Whiffed swings sample the ball's approach each frame and classify the
miss at swing expiry: tap too early (with ms), tap too late, ball line
wide, too high/low, out of reach. Balls that die on your side without
a swing log as PASSED with closest-approach data. Ring buffer of 50 at
T.G.missLog; the latest miss reason flashes on the HUD for 3.5s
(TUNE.missHud to disable). CPU serve-return benchmark still 11/12.

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

config.js

@@ -22,6 +22,7 @@ export const TUNE = {
   zMax: 6,          // shamblers on court at once
   zSplatQ: 0.5,     // min shot quality to splatter; below = stagger pushback
   zPushback: 1.4,   // m a staggered zombie is knocked back
+  missHud: 1,       // show the last miss reason on screen (full log: T.G.missLog)
 };
 
 export const COURT = { L: 23.77, W: 8.23, dblW: 10.97, netZ: 11.885, netH: 0.914, netW: 10.06 };