feat: 配方编辑器重写容量/椰子油逻辑

编辑器:
- 顶部容量选择: 单次/5ml/10ml/15ml/20ml/30ml/自定义
- 椰子油默认在最底行，单次时可编辑滴数(默认10)
- 非单次时椰子油自动填满(显示"约Xml")
- 实时提示：单次显示滴数+稀释比例，非单次显示总容量+填满+比例
- 新增精油插入到椰子油上方
- 编辑已有配方自动识别容量和稀释比例

其他:
- 拼音搜索改前缀匹配
- 输入法enter不触发保存
- 导出Excel移到标签行右侧小图标
- 新增→新增, 标签筛选→标签
- 配方名过长自动缩小
- 已审核标签viewer不可见
- ml显示整数

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

frontend/src/components/RecipeDetailOverlay.vue

@@ -842,6 +842,22 @@ onMounted(() => {
   })
   customOilNameEn.value = enMap
 
+  // Calculate current dilution ratio and volume from ingredients
+  const ings = r.ingredients || []
+  const coco = ings.find(i => i.oil === '椰子油')
+  const eoDrops = ings.filter(i => i.oil && i.oil !== '椰子油').reduce((s, i) => s + (i.drops || 0), 0)
+  const cocoDrops = coco ? (coco.drops || 0) : 0
+  const totalDrops = eoDrops + cocoDrops
+  if (eoDrops > 0 && cocoDrops > 0) {
+    dilutionRatio.value = Math.round(cocoDrops / eoDrops)
+  }
+  const ml = totalDrops / DROPS_PER_ML
+  if (ml <= 1.5) selectedVolume.value = 'single'
+  else if (Math.abs(ml - 5) < 1.5) selectedVolume.value = '5'
+  else if (Math.abs(ml - 10) < 3) selectedVolume.value = '10'
+  else if (Math.abs(ml - 30) < 8) selectedVolume.value = '30'
+  else { selectedVolume.value = 'custom'; customVolumeValue.value = Math.round(totalDrops); customVolumeUnit.value = 'drops' }
+
   loadBrand()
   nextTick(() => generateCardImage())
 })