[IMP] website_sale_aplicoop: improve i18n label fallbacks and response parsing

Add hardcoded fallback translations for es/eu when PO-based translation
returns the source string unchanged. Expand labels dict with all keys
needed by the frontend. Fix JSON response parsing in template
(data.result || data). Add js_translations keys. Add pot file for
stock_picking_batch_custom.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

website_sale_aplicoop/controllers/website_sale_i18n.py

@@ -43,15 +43,89 @@ def _get_translated_labels(self, lang=None, request_obj=None):
         lang = _get_detected_language(self, request_obj=req)
 
     env_lang = req.env(context=dict(req.env.context, lang=lang))
+    lang_code = (lang or "").split("_")[0]
+
+    fallbacks = {
+        "es": {
+            "Browse Product Categories": "Explorar categorías de productos",
+            "Save Draft": "Grabar pedido",
+            "Save order as draft": "Grabar pedido",
+            "Order saved as draft": "Pedido grabado",
+            "This order's cart is empty.": "El carrito de este pedido está vacío.",
+            "This order's cart is empty": "El carrito de este pedido está vacío",
+        },
+        "eu": {
+            "Browse Product Categories": "Produktu kategoriak arakatu",
+            "Save Draft": "Eskaera gorde",
+            "Save order as draft": "Eskaera gorde",
+            "Order saved as draft": "Eskaera gordeta",
+            "This order's cart is empty.": "Eskaera honen saskia hutsik dago.",
+            "This order's cart is empty": "Eskaera honen saskia hutsik dago",
+        },
+    }
+
+    def tr(source):
+        translated = env_lang._(source)
+        if translated == source:
+            translated = fallbacks.get(lang_code, {}).get(source, translated)
+        return translated
 
     labels = {
-        "product": env_lang._("Product"),
-        "quantity": env_lang._("Quantity"),
-        "price": env_lang._("Price"),
-        "subtotal": env_lang._("Subtotal"),
-        "total": env_lang._("Total"),
-        "empty": env_lang._("This order's cart is empty."),
-        # ... keep minimal set here; website_sale.py will fall back if needed
+        "product": tr("Product"),
+        "quantity": tr("Quantity"),
+        "price": tr("Price"),
+        "subtotal": tr("Subtotal"),
+        "total": tr("Total"),
+        "empty": tr("This order's cart is empty."),
+        "empty_cart": tr("This order's cart is empty."),
+        "browse_categories": tr("Browse Product Categories"),
+        "all_categories": tr("Browse Product Categories"),
+        "save_draft": tr("Save Draft"),
+        "save_order_as_draft": tr("Save order as draft"),
+        "order_saved_as_draft": tr("Order saved as draft"),
+        "save_cart": tr("Save Cart"),
+        "reload_cart": tr("Reload Cart"),
+        "proceed_to_checkout": tr("Proceed to Checkout"),
+        "confirm_order": tr("Confirm Order"),
+        "back_to_cart": tr("Back to Cart"),
+        "remove_item": tr("Remove Item"),
+        "cancel": tr("Cancel"),
+        "confirm": tr("Confirm"),
+        "confirmation": tr("Confirmation"),
+        "items": tr("items"),
+        "items_placeholder": tr("items"),
+        "added_to_cart": tr("added to cart"),
+        "cart_restored": tr("Your cart has been restored"),
+        "order_loaded": tr("Order loaded"),
+        "invalid_quantity": tr("Please enter a valid quantity"),
+        "connection_error": tr("Connection error"),
+        "error_unknown": tr("Unknown error"),
+        "error_saving_draft": tr("Error saving cart"),
+        "error_loading_draft": tr("Error loading draft"),
+        "error_processing_response": tr("Error processing response"),
+        "draft_saved": tr("Order saved as draft"),
+        "draft_saved_success": tr("Cart saved as draft successfully"),
+        "draft_loaded_success": tr("Draft order loaded successfully"),
+        "reload_draft_confirm": tr(
+            "Are you sure you want to load your last saved draft?"
+        ),
+        "reload_draft_replace": tr("This will replace the current items in your cart"),
+        "reload_draft_with": tr("with the saved draft."),
+        "clear_cart_confirm": tr(
+            "Are you sure you want to clear the cart? This will also cancel any saved draft order."
+        ),
+        "cart_cleared": tr("Cart cleared"),
+        "draft_cancelled": tr("draft order cancelled"),
+        "home_delivery": tr("Home Delivery"),
+        "delivery_information": tr("Delivery Information"),
+        "delivery_info_template": tr(
+            "Delivery Information: Your order will be delivered at {pickup_day} {pickup_date}"
+        ),
+        "important": tr("Important"),
+        "confirm_order_warning": tr(
+            "Once you confirm this order, you will not be able to modify it. Please review carefully before confirming."
+        ),
+        "pickup_day_label": tr("Pickup Day"),
     }
 
     return labels