feat: 套装卡片显示折扣率（会员价后再X折）

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/composables/useKitCost.js

@@ -86,11 +86,23 @@ export function useKitCost() {
     return KITS.map(kit => {
       const perDrop = calcKitPerDrop(kit)
       const recipes = getKitRecipes(kit)
+      // Calculate discount rate for display
+      const resolved = kit.oils.map(name => resolveOilName(name))
+      const bc = kit.bottleCount || {}
+      let totalBP = 0
+      for (const name of resolved) {
+        const meta = oils.oilsMeta[name]
+        totalBP += meta ? meta.bottlePrice * (bc[name] || 1) : 0
+      }
+      const totalValue = totalBP + (kit.accessoryValue || 0)
+      const discountRate = totalValue > 0 ? Math.min(kit.price / totalValue, 1) : 1
+
       return {
         ...kit,
         perDrop,
         recipes,
         recipeCount: recipes.length,
+        discountRate,
       }
     }).sort((a, b) => a.recipeCount - b.recipeCount)
   })

frontend/src/views/KitExport.vue

@@ -22,6 +22,7 @@
       >
         <div class="kit-name">{{ ka.name }}</div>
         <div class="kit-price">¥{{ ka.price }}</div>
+        <div class="kit-discount">会员价后再{{ (ka.discountRate * 10).toFixed(1) }}折</div>
         <div class="kit-stats">
           <span>{{ ka.oils.length }} 种精油</span>
           <span class="kit-recipe-count">可做 {{ ka.recipeCount }} 个配方</span>
@@ -416,7 +417,8 @@ async function exportExcel(mode) {
   box-shadow: 0 2px 8px rgba(74, 157, 126, 0.15);
 }
 .kit-name { font-weight: 600; font-size: 14px; color: #3e3a44; margin-bottom: 4px; }
-.kit-price { font-size: 18px; font-weight: 700; color: #4a9d7e; margin-bottom: 6px; }
+.kit-price { font-size: 18px; font-weight: 700; color: #4a9d7e; margin-bottom: 2px; }
+.kit-discount { font-size: 11px; color: #e65100; margin-bottom: 6px; }
 .kit-stats { font-size: 12px; color: #6b6375; display: flex; flex-direction: column; gap: 2px; }
 .kit-recipe-count { color: #4a9d7e; font-weight: 500; }