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/cypress/e2e/pr27-features.cy.js

@@ -175,6 +175,85 @@ describe('PR27 Feature Tests', () => {
     })
   })
 
+  // -------------------------------------------------------------------------
+  // API: rename recipe auto-retranslates en_name
+  // -------------------------------------------------------------------------
+  describe('API: rename recipe retranslates en_name', () => {
+    let recipeId
+
+    after(() => {
+      if (recipeId) {
+        cy.request({ method: 'DELETE', url: `/api/recipes/${recipeId}`, headers: authHeaders, failOnStatusCode: false })
+      }
+    })
+
+    it('creates recipe then renames it, en_name auto-updates', () => {
+      cy.request({
+        method: 'POST', url: '/api/recipes', headers: authHeaders,
+        body: { name: '头痛', ingredients: [{ oil_name: '薰衣草', drops: 3 }], tags: [] }
+      }).then(res => {
+        recipeId = res.body.id
+        // Verify initial en_name
+        cy.request('/api/recipes').then(list => {
+          const r = list.body.find(x => x.id === recipeId)
+          expect(r.en_name).to.include('Headache')
+        })
+        // Rename to 肩颈按摩
+        cy.request({
+          method: 'PUT', url: `/api/recipes/${recipeId}`, headers: authHeaders,
+          body: { name: '肩颈按摩' }
+        }).then(() => {
+          cy.request('/api/recipes').then(list => {
+            const r = list.body.find(x => x.id === recipeId)
+            expect(r.en_name).to.include('Neck')
+            expect(r.en_name).to.include('Massage')
+          })
+        })
+      })
+    })
+  })
+
+  // -------------------------------------------------------------------------
+  // API: delete user skips duplicate diary by ingredient content
+  // -------------------------------------------------------------------------
+  describe('API: delete user skips duplicate diary', () => {
+    const DUP_USER = 'cypress_pr27_dup'
+
+    it('creates user with duplicate diary, deletes, verifies skip', () => {
+      // Create user
+      cy.request({
+        method: 'POST', url: '/api/users', headers: authHeaders,
+        body: { username: DUP_USER, display_name: 'Dup Test', role: 'viewer' }
+      }).then(res => {
+        const userId = res.body.id
+        const userToken = res.body.token
+        const userAuth = { Authorization: `Bearer ${userToken}` }
+
+        // Get a public recipe's ingredients to create a duplicate
+        cy.request({ url: '/api/recipes', headers: authHeaders }).then(listRes => {
+          const pub = listRes.body[0]
+          const dupIngs = pub.ingredients.map(i => ({ oil: i.oil_name, drops: i.drops }))
+
+          // Add diary with same ingredients as public recipe (different name)
+          cy.request({
+            method: 'POST', url: '/api/diary', headers: userAuth,
+            body: { name: '我的重复方', ingredients: dupIngs, note: '' }
+          }).then(() => {
+            // Delete user
+            cy.request({ method: 'DELETE', url: `/api/users/${userId}`, headers: authHeaders }).then(delRes => {
+              expect(delRes.body.ok).to.eq(true)
+              // Verify duplicate was NOT transferred
+              cy.request({ url: '/api/diary', headers: authHeaders }).then(diaryRes => {
+                const transferred = diaryRes.body.find(d => d.name && d.name.includes('我的重复方'))
+                expect(transferred).to.not.exist
+              })
+            })
+          })
+        })
+      })
+    })
+  })
+
   // -------------------------------------------------------------------------
   // UI: 管理配方 login prompt when not logged in
   // -------------------------------------------------------------------------