feat: ask replace vs save-to-archive on regenerate recipe

When user clicks 'Generate another', show a choice:
- Replace (discard current, generate new) — former behavior
- Save to archive & generate new — saves current recipe first

All 5 languages (it/en/de/fr/es) with regen_choice_title,
regen_replace, regen_save_new keys.

translations/en.json

@@ -361,6 +361,9 @@
         "loading_msg": "Preparing your recipe...",
         "start_cooking": "👨‍🍳 Cooking Mode",
         "regenerate": "🔄 Generate another one",
+        "regen_choice_title": "What do you want to do with this recipe?",
+        "regen_replace": "🔄 Generate another (discard this one)",
+        "regen_save_new": "💾 Save to archive & generate a new one",
         "close_btn": "✅ Close",
         "ingredients_title": "🧾 Ingredients",
         "tools_title": "Equipment needed",