feat: game state, persistence, UI framework (Alpine+Tailwind), economy system (#10, #11, #12)

- Game state with localStorage save/load + reset (type DELETE to confirm)
- Alpine.js + Tailwind CSS + Lucide UI overlay (HUD bar, shop modal, settings, toasts)
- Economy: fish prices, tank tier costs/capacities, rarity multipliers, sell value formula
- Genetic system: hue/saturation/size/speed/pattern/rarity/gender + breeding inheritance
- Fish selection via raycaster (click fish = select, click empty = drop food)
- Buy/Sell/Breed/Upgrade actions wired to game state

package.json

@@ -9,10 +9,13 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "alpinejs": "^3.17.4",
     "three": "^0.182.0"
   },
   "devDependencies": {
+    "@tailwindcss/vite": "^4.3.3",
     "@types/three": "^0.182.0",
+    "tailwindcss": "^4.3.3",
     "typescript": "^5.8.3",
     "vite": "^7.0.0"
   }