fix: 存为我的改用自定义 showPrompt，与主分支保持一致

将 saveToDiary 中的原生 prompt() 替换为项目内置的
showPrompt()，使对话框样式与主分支及全站风格保持一致。

Co-Authored-By: YoYo <yoyo@euphon.net>

frontend/src/components/RecipeDetailOverlay.vue

@@ -355,7 +355,7 @@ import { useAuthStore } from '../stores/auth'
 import { useUiStore } from '../stores/ui'
 import { useDiaryStore } from '../stores/diary'
 import { api } from '../composables/useApi'
-import { showConfirm } from '../composables/useDialog'
+import { showConfirm, showPrompt } from '../composables/useDialog'
 import { oilEn, recipeNameEn } from '../composables/useOilTranslation'
 // TagPicker replaced with inline tag editing
 
@@ -631,7 +631,7 @@ async function saveToDiary() {
     ui.openLogin(() => saveToDiary())
     return
   }
-  const name = prompt('保存为我的配方，名称：', recipe.value.name)
+  const name = await showPrompt('保存为我的配方，名称：', recipe.value.name)
   if (!name) return
   try {
     await api.post('/api/diary', {