Persist recipe English name translation to database

- Add en_name column to recipes table (migration in database.py)
- Include en_name in recipe API responses and RecipeUpdate model
- Save en_name when admin/senior_editor applies translation
- Load en_name on overlay open, so translation persists across sessions

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

frontend/src/stores/recipes.js

@@ -16,6 +16,7 @@ export const useRecipesStore = defineStore('recipes', () => {
       _owner_name: r._owner_name ?? r.owner_name ?? '',
       _version: r._version ?? r.version ?? 1,
       name: r.name,
+      en_name: r.en_name ?? '',
       note: r.note ?? '',
       tags: r.tags ?? [],
       ingredients: (r.ingredients ?? []).map((ing) => ({