Update default prices via CSV without changing sales-channel prices
Bulk update each SKU's default price record with a CSV while leaving sales-channel prices untouched.
The bulk 'update default price via CSV' flow updates only each SKU's default price record.
Channels that follow the default show the new values immediately.
The upload is strict and all-or-nothing: rows may only carry the SKU identifier plus the default-price data, any other column makes the entire upload fail validation, and nothing is applied on failure.
If any SKU in the file is not part of the workspace being updated, the whole upload is rejected as unauthorized rather than skipping that row.