cleanup: delete computed-stats.ts shim and store/index.ts

- Delete src/lib/game/computed-stats.ts (root-level re-export shim)
- Delete src/lib/game/store/index.ts (nothing imports from it)
- Update __tests__/computed-stats.test.ts to import from ../utils instead
- Clean up craftingStore.ts imports (remove unused useGameStore, CraftingApply)

Typecheck and lint pass (pre-existing DisciplinesTab.tsx errors unchanged)

src/components/game/crafting/EnchantmentPreparer.tsx

@@ -14,7 +14,7 @@ import { EQUIPMENT_TYPES } from '@/lib/game/data/equipment';
 import type { EquipmentInstance, AppliedEnchantment, LootInventory, EquipmentCraftingProgress } from '@/lib/game/types';
 import type { EquipmentSlot } from '@/lib/game/types';
 import { fmt } from '@/lib/game/stores';
-import { useGameStore, useCraftingStore, useManaStore, useSkillStore } from '@/lib/game/stores';
+import { useGameStore, useCraftingStore, useManaStore } from '@/lib/game/stores';
 import { useGameToast } from '@/components/game/GameToast';
 
 export interface EnchantmentPreparerProps {
@@ -31,7 +31,6 @@ export function EnchantmentPreparer({
   const equipmentInstances = useCraftingStore((s) => s.equipmentInstances);
   const preparationProgress = useCraftingStore((s) => s.preparationProgress);
   const rawMana = useManaStore((s) => s.rawMana);
-  const skills = useSkillStore((s) => s.skills);
   const startPreparing = useCraftingStore((s) => s.startPreparing);
   const cancelPreparation = useCraftingStore((s) => s.cancelPreparation);