[ADD] website_sale_aplicoop: botón limpiar carrito en sidebar

Añade botón 'Clear Cart' (fa-trash) en el header y footer del sidebar
del carrito en la página de lista de productos.

Cambios:
- views/website_templates.xml: botón clear-cart-btn en card-header y
  clear-cart-btn-footer en card-footer del sidebar
- controllers/website_sale.py: nuevo endpoint POST /eskaera/clear-cart
  que cancela el sale.order borrador del usuario si existe
- static/src/js/website_sale.js: método _clearCart(), listeners para
  ambos botones (header + footer)
- models/js_translations.py: nuevas cadenas clear_cart, clear_cart_confirm,
  cart_cleared, draft_cancelled
- i18n/es.po, i18n/eu.po: traducciones ES y EU de los nuevos labels

website_sale_aplicoop/controllers/website_sale.py

@@ -268,6 +268,13 @@ class AplicoopWebsiteSale(WebsiteSale):
             "items": env_lang._("items"),
             "added_to_cart": env_lang._("added to cart"),
             "out_of_stock": env_lang._("Out of stock"),
+            # ============ CLEAR CART ============
+            "clear_cart": env_lang._("Clear Cart"),
+            "clear_cart_confirm": env_lang._(
+                "Are you sure you want to clear the cart? This will also cancel any saved draft order."
+            ),
+            "cart_cleared": env_lang._("Cart cleared"),
+            "draft_cancelled": env_lang._("draft order cancelled"),
         }
 
         return labels
@@ -2415,6 +2422,107 @@ class AplicoopWebsiteSale(WebsiteSale):
                 status=500,
             )
 
+    @http.route(
+        ["/eskaera/clear-cart"],
+        type="http",
+        auth="user",
+        website=True,
+        methods=["POST"],
+        csrf=False,
+    )
+    def clear_cart(self, **post):
+        """Clear the user's cart and cancel any existing draft sale.order.
+
+        Receives: JSON body with 'order_id'
+        Returns: JSON with success status and cancelled_order_id if applicable.
+        """
+        try:
+            data = self._decode_json_body()
+        except ValueError as e:
+            return request.make_response(
+                json.dumps({"error": str(e)}),
+                [("Content-Type", "application/json")],
+                status=400,
+            )
+
+        order_id = data.get("order_id")
+        if not order_id:
+            return request.make_response(
+                json.dumps({"error": "order_id is required"}),
+                [("Content-Type", "application/json")],
+                status=400,
+            )
+        try:
+            order_id = int(order_id)
+        except (ValueError, TypeError):
+            return request.make_response(
+                json.dumps({"error": f"Invalid order_id format: {order_id}"}),
+                [("Content-Type", "application/json")],
+                status=400,
+            )
+
+        group_order = request.env["group.order"].sudo().browse(order_id)
+        if not group_order.exists():
+            return request.make_response(
+                json.dumps({"error": f"Order {order_id} not found"}),
+                [("Content-Type", "application/json")],
+                status=404,
+            )
+
+        current_user = request.env.user
+        if not current_user.partner_id:
+            return request.make_response(
+                json.dumps({"error": "User has no associated partner"}),
+                [("Content-Type", "application/json")],
+                status=400,
+            )
+
+        # Find and cancel any existing draft sale.order for this period
+        cancelled_order_id = None
+        try:
+            draft_orders = self._find_recent_draft_order(
+                current_user.partner_id.id, group_order
+            )
+            if draft_orders:
+                draft_order = draft_orders[0]
+                cancelled_order_id = draft_order.id
+                # Use action_cancel if available, otherwise unlink
+                if draft_order.state == "draft":
+                    draft_order.sudo().action_cancel()
+                    _logger.info(
+                        "clear_cart: Cancelled draft sale.order %d for partner %d",
+                        draft_order.id,
+                        current_user.partner_id.id,
+                    )
+                else:
+                    _logger.info(
+                        "clear_cart: Draft order %d already in state '%s', skipping cancel",
+                        draft_order.id,
+                        draft_order.state,
+                    )
+        except Exception as e:
+            _logger.warning(
+                "clear_cart: Error cancelling draft order for partner %d: %s",
+                current_user.partner_id.id,
+                str(e),
+            )
+
+        response_data = {
+            "success": True,
+            "message": request.env._("Cart cleared"),
+            "cancelled_order_id": cancelled_order_id,
+        }
+        _logger.info(
+            "clear_cart: Cart cleared for partner %d, order %d (cancelled_sale_order: %s)",
+            current_user.partner_id.id,
+            order_id,
+            cancelled_order_id,
+        )
+        return request.make_response(
+            json.dumps(response_data),
+            [("Content-Type", "application/json")],
+        )
+
     @http.route(
         ["/eskaera/save-order"],
         type="http",