-- Same drift as make_charges_tariff_id_nullable.sql, second column: live
-- production `charges.group_id` was NOT NULL with no default, but manual
-- charge entry (PaymentController::storeCharge()) has never supplied
-- group_id either — see its docblock, which documents this as intentional,
-- matching the decommissioned legacy insert. The repo's own schema
-- (docker/mysql/init/000_schema.sql) has always declared this column
-- `INT NULL`.
--
-- Safe to run once; if the column is already nullable this is a no-op.

ALTER TABLE charges MODIFY group_id INT NULL;
