[Guided import]: Blank Source_Identifier Rows are flagged as identical

[ndroark]

Description

Blank cells in the Source_Identifier column are flagged as identical, hence an error.

Which step?

Which step of the guided import did the bug occur on?

• Step 1 – Configure importer / select admin set / upload CSV (and optional zip)
• Step 2 – Validation (results, errors, or warnings)
• Step 3 – Review / run import
• Other (describe):

Steps to reproduce

1. Start a new guided import (e.g. from the importer list).
2. On Step 1: select default admin set; upload CSV with blank cells in the Source_Identifier field.
3. See that the validator reports this as an error.

Expected behavior

Blank Source_Identifier fields should be accepted, as the system will assign a unique source identifier when the CSV doesn't specify one.

Actual behavior

Blank Source_Identifier fields are flagged as errors.

Screenshots

Additional context

Any other details (e.g. custom field mappings, multi-tenant, specific work type) that might matter.

If someone's installation is set to require this field to be populated, blank fields should be noted, not because they are identical, but because it is a required field.

[laritakr]

Addressed by #1156