[FIX] website_sale_aplicoop: lint fixes (exception chaining, imports, remove unused vars)

website_sale_aplicoop/controllers/exceptions.py

@@ -0,0 +1,17 @@
+"""Shared exceptions for website_sale_aplicoop controllers helpers.
+
+These are imported by helper modules to avoid circular imports with
+`website_sale.py` when splitting helpers into separate files.
+"""
+
+
+class BadRequestError(Exception):
+    pass
+
+
+class ForbiddenError(Exception):
+    pass
+
+
+class GroupOrderUnavailable(Exception):
+    pass