Thumb-scale draw meter, looser aim magnet, a bomb worth the tin

- The draw meter is a fixed bar across the bottom, ~90% of the width and 10px
  tall, with the kill notch on it. It was a 26x4 stub floating on the apron by
  the player's feet, which is nothing under a thumb at arm's length. The serve
  hint is suppressed while pulling since they share the slot. pullFull 95 -> 130:
  at 95 every pull maxed out by accident, so the meter never meant anything.
- The aim magnet took the nearest body ALONG the lane, so a close shambler a
  little off-axis stole shots clearly aimed past it. It now picks the best
  ALIGNED body, with TUNE.aimTie of slack in which a nearer one still wins — a
  straight-ahead lane still eats the nearest body first, which is the settled
  feel. aimTie: 1 restores the old behaviour exactly, for A/B.
- Bomb radius 2.5 -> 4.2 (2 kills -> 5 in a scattered ten-wave), a 120-particle
  eruption, a ring of thrown stains and a full-size pile. The blinding white
  frame is now a brief warm bloom — it was hiding the very gore it announced.
- Rack tiles 22 -> 30 tall, and the touch band is padded above and runs to the
  screen edge below. At 22 logical px they were ~30 CSS px on a phone, well under
  the ~44 a thumb expects; now ~62.

26-game soak clean with heavy bomb use, arrays stay bounded. Serve returns
136/150 = 90.7% +/-2.4%, 30 human-tapped points = 50 hits / 0 whiffs.

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

config.js

@@ -47,13 +47,20 @@ export const TUNE = {
   // reaching a far shambler must not cost a longer drag than the screen has room for. The old
   // mapping (pull length = reach) is why you had to drag off the bottom of the phone.
   pullMin: 18,      // px of pull below which the release cancels — no shot, nothing spent
-  pullFull: 95,     // px of pull for a full-power shot. Keep this well inside one thumb's travel.
+  pullFull: 130,    // px of pull for a full-power shot. Keep this well inside one thumb's travel — but
+                    // 95 was so short that EVERY pull maxed out by accident and the meter never
+                    // meant anything. A full draw should cost a deliberate stretch of the thumb.
+                    // Capped short of ~150 because a pull that STARTS low on the screen has to
+                    // still be completable downward before the finger runs off the glass.
   pullQMin: 0.12,   // shot quality at pullMin, scaling to 1.0 (= PERFECT) at pullFull. Below
                     // zSplatQ it only staggers, so a lazy flick can't kill: THE anti-spam knob.
   aimCone: 0.10,    // lane half-width added per meter of range. This is what makes the pull's ANGLE
                     // mean something: at 0.45 the cone was ±10 m at the far baseline — the whole
                     // court — so every downward pull picked the same body and the angle felt inert.
                     // 0.10 gives ±2.9 m out there: you have to actually point at a lane.
+  aimTie: 0.12,     // how much worse-aimed a NEARER body may be and still win the lane (0..1 of the
+                    // cone half-width). 0 = pure best-aligned wins; 1 = the old "nearest in the
+                    // lane always wins", which is what made the magnet grab the wrong shambler.
   aimReach: 22,     // m the aim ray runs when no shambler stands in the lane
   // How the camera moves while you're drawing the slingshot. NEGATIVE (the default) drops it and
   // pushes in — you crouch into the shot. POSITIVE lifts it and leans back for a steeper, more
@@ -76,8 +83,10 @@ export const TUNE = {
   tinFlames: 3,     // flame balls in a fresh tin
   tinGuns: 1,       // machine-gun charges in a fresh tin
   wCap: 9,          // per-type cap on the courtside rack — tins accumulate, but only so many
-  rackH: 22,        // px height of the bottom weapon rack (feel knob: how much court it covers)
-  bombRadius: 2.5,  // m blast radius of a bomb ball
+  rackH: 30,        // px height of the bottom weapon rack (feel knob: how much court it covers).
+                    // 22 logical px is ~30 CSS px on a phone — under half Apple's 44px target, which
+                    // is why switching tins felt fiddly. rackHit also pads the touch band (render.js).
+  bombRadius: 4.2,  // m blast radius of a bomb ball — 2.5 barely cleared the bodies stood on the crater
   hordeLen: 12,     // s a horde wave lasts
   hordeRate: 2.5,   // zombies spawned per second during a horde
   mgRate: 6,        // machine-gun pellets fired per second during a horde