fix: apply Crafting Efficiency cost reduction to all fabrication paths

- Add getCraftingCostReduction() and applyCostReduction() helpers in crafting-fabricator.ts
- Apply cost reduction in deductMaterials() and checkFabricatorCosts()
- Apply cost reduction in startFabricatorCrafting() and cancelEquipmentCrafting() pipeline
- Update canCraftRecipe() in fabricator-recipes.ts to accept costReduction param
- Update FabricatorSubTab and MaterialRecipeCard UIs to display discounted costs
- Spec formula: actualCost = ceil(baseCost × (1 - craftingCostReduction / 100))

Fixes #316

src/components/game/tabs/CraftingTab/MaterialRecipeCard.tsx

@@ -8,6 +8,7 @@ import { canCraftRecipe } from '@/lib/game/data/fabricator-recipes';
 import { MANA_TYPE_LABELS } from '@/lib/game/data/fabricator-recipe-types';
 import type { FabricatorRecipe } from '@/lib/game/data/fabricator-recipes';
 import { DebugName } from '@/components/game/debug/debug-context';
+import { getCraftingCostReduction, applyCostReduction } from '@/lib/game/crafting-fabricator';
 
 interface MaterialRecipeCardProps {
   recipe: FabricatorRecipe;
@@ -15,6 +16,7 @@ interface MaterialRecipeCardProps {
   rawMana: number;
   elementalMana: Record<string, { current: number; max: number; unlocked: boolean }>;
   onCraft: (recipe: FabricatorRecipe) => void;
+  costReduction?: number;
 }
 
 export function MaterialRecipeCard({
@@ -23,11 +25,12 @@ export function MaterialRecipeCard({
   rawMana,
   elementalMana,
   onCraft,
+  costReduction = 0,
 }: MaterialRecipeCardProps) {
   const pool = recipe.manaType === 'raw'
     ? rawMana
     : (elementalMana[recipe.manaType]?.current ?? 0);
-  const { canCraft } = canCraftRecipe(recipe, materials, pool, recipe.manaType);
+  const { canCraft } = canCraftRecipe(recipe, materials, pool, recipe.manaType, costReduction);
   const resultDrop = recipe.resultMaterial ? LOOT_DROPS[recipe.resultMaterial] : null;
   const resultRarity = resultDrop ? LOOT_RARITY_COLORS[resultDrop.rarity] : null;
 
@@ -57,16 +60,20 @@ export function MaterialRecipeCard({
         {Object.keys(recipe.materials).length > 0 && (
           <>
             <div className="text-gray-500">Input Materials:</div>
-            {Object.entries(recipe.materials).map(([matId, amount]) => {
+            {Object.entries(recipe.materials).map(([matId, rawAmount]) => {
+              const reducedAmount = applyCostReduction(rawAmount, costReduction);
               const available = materials[matId] || 0;
               const matDrop = LOOT_DROPS[matId];
-              const hasEnough = available >= amount;
+              const hasEnough = available >= reducedAmount;
 
               return (
                 <div key={matId} className="flex justify-between">
                   <span>{matDrop?.name ?? matId}</span>
                   <span className={hasEnough ? 'text-green-400' : 'text-red-400'}>
-                    {available} / {amount}
+                    {available} / {reducedAmount}
+                    {costReduction > 0 && rawAmount !== reducedAmount && (
+                      <span className="text-gray-500 ml-1">(was {rawAmount})</span>
+                    )}
                   </span>
                 </div>
               );