Report accurate horse stats from compass

[grepsedawk]

Problem

The compass horse checker (right-click a horse with a compass) reported wrong stats:

• Jump height came from a curve-fitted polynomial that was never accurate and drifted further from reality as jump strength rose. A boosted horse that actually reaches ~5.4 blocks (as shown by mods like Jade) was reported as 4.9.
• Speed used a stale conversion constant.
• All stats were read from the attribute base value, which hides modifiers from gear, potions, or other plugins.

Fix

• Jump height: simulate the real jump instead of approximating. Each tick the horse rises by its velocity, then velocity falls by gravity (0.08) and is scaled by drag (0.98); the peak is the sum of the upward velocities. Verified against decompiled 1.21.x LivingEntity physics.

  jump strength	old (polynomial)	new (physics)
  0.5	1.62	1.71
  0.9	4.43	4.90
  0.955	4.90	5.46
  1.0	5.29	5.92

• Speed: update the constant from 42.158 to 43.17037 (= 14.57 b/s ÷ 0.3375), matching the current horse speed table (4.86 / 9.71 / 14.57 b/s).

• Effective values: read every stat via getValue() instead of getBaseValue(), so modifiers (gear, potions, other plugins) are reflected. FasterHorses sets the base value, so its speeds were already shown — this also covers modifier-based changes.

Module compiles.