feat: 非精油产品(drop_count=1)显示"份"而非"滴"

oils store新增 unitLabel/unitLabelPlural，根据 dropCount 判断：
- 精油(dropCount>1): 滴/drop
- 护肤品等(dropCount=1): 份/portion
影响: 配方卡片、个人配方、库存匹配、去重提示

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

frontend/src/components/RecipeDetailOverlay.vue

@@ -64,7 +64,7 @@
             <ul style="list-style:none;margin-bottom:20px;padding:0">
               <li v-for="(ing, i) in cardIngredients" :key="i" class="ec-ing">
                 <span class="ec-oil-name">{{ getCardOilName(ing.oil) }}</span>
-                <span class="ec-drops">{{ ing.drops }} {{ cardLang === 'en' ? (ing.drops === 1 ? 'drop' : 'drops') : '滴' }}</span>
+                <span class="ec-drops">{{ ing.drops }} {{ oilsStore.unitLabelPlural(ing.oil, ing.drops, cardLang) }}</span>
                 <span class="ec-cost">{{ oilsStore.fmtPrice(oilsStore.pricePerDrop(ing.oil) * ing.drops) }}</span>
                 <span v-if="hasRetailForOil(ing.oil) && retailPerDrop(ing.oil) > oilsStore.pricePerDrop(ing.oil)" class="ec-retail">{{ oilsStore.fmtPrice(retailPerDrop(ing.oil) * ing.drops) }}</span>
               </li>

frontend/src/stores/oils.js

@@ -93,6 +93,21 @@ export const useOilsStore = defineStore('oils', () => {
     delete oilsMeta.value[name]
   }
 
+  function isPortionUnit(name) {
+    const meta = oilsMeta.value[name]
+    return meta && meta.dropCount === 1
+  }
+
+  function unitLabel(name, lang = 'zh') {
+    if (isPortionUnit(name)) return lang === 'en' ? 'portion' : '份'
+    return lang === 'en' ? 'drop' : '滴'
+  }
+
+  function unitLabelPlural(name, count, lang = 'zh') {
+    if (isPortionUnit(name)) return lang === 'en' ? (count === 1 ? 'portion' : 'portions') : '份'
+    return lang === 'en' ? (count === 1 ? 'drop' : 'drops') : '滴'
+  }
+
   return {
     oils,
     oilsMeta,
@@ -105,5 +120,8 @@ export const useOilsStore = defineStore('oils', () => {
     loadOils,
     saveOil,
     deleteOil,
+    isPortionUnit,
+    unitLabel,
+    unitLabelPlural,
   }
 })

frontend/src/views/Inventory.vue

@@ -76,7 +76,7 @@
             class="match-ing"
             :class="{ missing: !ownedSet.has(ing.oil) }"
           >
-            {{ ing.oil }} {{ ing.drops }}滴
+            {{ ing.oil }} {{ ing.drops }}{{ oils.unitLabel(ing.oil) }}
           </span>
         </div>
         <div class="match-meta">

frontend/src/views/MyDiary.vue

@@ -31,7 +31,7 @@
           <div class="diary-name">{{ d.name || '未命名' }}</div>
           <div class="diary-ings">
             <span v-for="ing in (d.ingredients || []).slice(0, 3)" :key="ing.oil" class="diary-ing">
-              {{ ing.oil }} {{ ing.drops }}滴
+              {{ ing.oil }} {{ ing.drops }}{{ oils.unitLabel(ing.oil) }}
             </span>
             <span v-if="(d.ingredients || []).length > 3" class="diary-more">+{{ (d.ingredients || []).length - 3 }}</span>
           </div>

frontend/src/views/RecipeManager.vue

@@ -1019,8 +1019,8 @@ async function checkDupName(name, ings, target = 'diary') {
       return false
     }
 
-    const existIngs = dupIngs.map(i => `${i.oil}${i.drops}滴`).join('、')
-    const newIngs = myIngs.map(i => `${i.oil}${i.drops}滴`).join('、')
+    const existIngs = dupIngs.map(i => `${i.oil}${i.drops}${oils.unitLabel(i.oil)}`).join('、')
+    const newIngs = myIngs.map(i => `${i.oil}${i.drops}${oils.unitLabel(i.oil)}`).join('、')
     const ok = await showConfirm(
       `${where}中已有同名配方「${currentName}」，内容不同：\n\n已有：${existIngs}\n新的：${newIngs}\n\n请改名后保存`,
       { okText: '改名', cancelText: '取消' }