test: 补充recipeNameEn翻译、重复精油、改名重翻译、去重跳过测试

单元测试256个全部通过（新增14个）:
- recipeNameEn: 11个翻译测试
- 重复精油检查: 3个
后端: 补充"缓解"翻译词条
E2E: 改名重翻译、删除用户去重跳过

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

frontend/src/__tests__/pr27Features.test.js

@@ -1,4 +1,5 @@
 import { describe, it, expect } from 'vitest'
+import { recipeNameEn } from '../composables/useOilTranslation'
 
 // ---------------------------------------------------------------------------
 // EDITOR_ONLY_TAGS includes '已下架'
@@ -84,3 +85,88 @@ describe('已下架 tag filtering', () => {
     expect(filterDelisted(all)).toHaveLength(0)
   })
 })
+
+// ---------------------------------------------------------------------------
+// recipeNameEn — front-end keyword translation
+// ---------------------------------------------------------------------------
+describe('recipeNameEn', () => {
+  it('translates 酸痛包 → Pain Relief Blend', () => {
+    expect(recipeNameEn('酸痛包')).toBe('Pain Relief Blend')
+  })
+
+  it('translates 助眠配方 → Sleep Aid Blend', () => {
+    expect(recipeNameEn('助眠配方')).toBe('Sleep Aid Blend')
+  })
+
+  it('translates 头痛 → Headache', () => {
+    expect(recipeNameEn('头痛')).toBe('Headache')
+  })
+
+  it('translates 肩颈按摩 → Neck & Shoulder Massage', () => {
+    expect(recipeNameEn('肩颈按摩')).toBe('Neck & Shoulder Massage')
+  })
+
+  it('translates 湿疹舒缓 → Eczema Soothing', () => {
+    expect(recipeNameEn('湿疹舒缓')).toBe('Eczema Soothing')
+  })
+
+  it('translates 淋巴排毒 → Lymph Detox', () => {
+    expect(recipeNameEn('淋巴排毒')).toBe('Lymph Detox')
+  })
+
+  it('translates 灰指甲 → Nail Fungus', () => {
+    expect(recipeNameEn('灰指甲')).toBe('Nail Fungus')
+  })
+
+  it('translates 缓解焦虑 → Relief Anxiety', () => {
+    expect(recipeNameEn('缓解焦虑')).toBe('Relief Anxiety')
+  })
+
+  it('returns original name for unknown text', () => {
+    expect(recipeNameEn('XYZXYZ')).toBe('XYZXYZ')
+  })
+
+  it('returns empty/null for empty/null input', () => {
+    expect(recipeNameEn('')).toBe('')
+    expect(recipeNameEn(null)).toBeNull()
+  })
+
+  it('does not duplicate keywords', () => {
+    // 酸痛 maps to Pain Relief; should not appear twice
+    const result = recipeNameEn('酸痛酸痛')
+    expect(result).toBe('Pain Relief')
+  })
+})
+
+// ---------------------------------------------------------------------------
+// Duplicate oil prevention logic
+// ---------------------------------------------------------------------------
+describe('duplicate oil prevention', () => {
+  it('detects duplicate oil in ingredient list', () => {
+    const ings = [
+      { oil: '薰衣草', drops: 3 },
+      { oil: '茶树', drops: 2 },
+    ]
+    const newOil = '薰衣草'
+    const isDup = ings.some(i => i.oil === newOil)
+    expect(isDup).toBe(true)
+  })
+
+  it('allows non-duplicate oil', () => {
+    const ings = [
+      { oil: '薰衣草', drops: 3 },
+      { oil: '茶树', drops: 2 },
+    ]
+    const newOil = '乳香'
+    const isDup = ings.some(i => i.oil === newOil)
+    expect(isDup).toBe(false)
+  })
+
+  it('allows same oil for the same row (editing current)', () => {
+    const ing = { oil: '薰衣草', drops: 3 }
+    const ings = [ing, { oil: '茶树', drops: 2 }]
+    // When selecting for the same row, exclude self
+    const isDup = ings.some(i => i !== ing && i.oil === '薰衣草')
+    expect(isDup).toBe(false)
+  })
+})