Rebalance weapon tiers via quantitative DPS/range/accuracy/pool scoring

tools/score_weapons.js ranks the arsenal with a behavior-aware model:
effective DPS (bounce/boomerang/AoE/DoT multipliers), real engagement range,
spread-based accuracy, and damage pool per ammo load. Tier moves:
- Cleaver Cadence 0->1 (440px range + return re-hit outguns the starters)
- Bile Blunderbuss 1->2 (134 effDPS + slow + pools is secretly a heavy)
- The Cauterizer 2->3 (252 effDPS, highest sustained DPS in the game)
- The Tenderizer 2->3 (134 effDPS AoE, outscores Spinal Tap)

Tiers now: T0 repeater/marrow, T1 cleaver/saw/hemophage/eye,
T2 bile/guthook/fleshmasher/trapqueen/redhand, T3 cauterizer/tenderizer/
spinaltap/swarmjar. Smoke test pins the 2/4/5/4 distribution.

test/smoke.js

@@ -147,6 +147,8 @@ check('every weapon has layered render and muzzle geometry', Object.values(ctx.W
   Number.isFinite(w.torsoW) && Number.isFinite(w.torsoFwd) && Number.isFinite(w.muzzle) && w.muzzle > 0));
 check('every weapon has finite impact punch metadata', Object.values(ctx.WEAPONS).every(w => Number.isFinite(w.punch) && w.punch > 0));
 check('arsenal still contains exactly 16 weapons', Object.keys(ctx.WEAPONS).length === 16);
+check('quantitative tier rebalance: 2/4/5/4 distribution', [0, 1, 2, 3].every(t => Object.values(ctx.WEAPONS).filter(w => w.tier === t).length === [2, 4, 5, 4][t]));
+check('every drop tier has at least one weapon', [0, 1, 2, 3].every(t => Object.values(ctx.WEAPONS).some(w => w.tier === t)));
 check('visceral DSP and fallback events are wired',
   ['punch', 'duck', 'wallHit', 'lifesteal'].every(name => typeof ctx.Sfx[name] === 'function'));
 const missingSfxFiles = Object.values(ctx.SfxBank.FILES).filter(file => {