Default new certificate page title to courseware title

[zamanafzal]

What are the relevant tickets?

Follow-up to the certificate-title work (hq#11907, tracked in hq#11938). Covers item B.

Description

A certificate page can show PLACEHOLDER - <name> Certificate in its "Certificate Title" (CertificatePage.product_name), because that's what the create_courseware command populates when it creates the page. If nobody edits it afterward, the certificate goes out with that placeholder title. This changes the default to the courseware (course/program) title so command-created certificate pages are display-ready out of the box.

This only happens via create_courseware — when an admin creates a certificate page directly in the CMS, the "Certificate Title" field starts empty and they type the real title, so no placeholder is ever produced there.

• Matters now because the Certificate Title flows into the verifiable credential and the LinkedIn "Add to Profile" name, so a leftover PLACEHOLDER - … title would leak into a signed credential.
• The Step-1 backfill (#3697) cleans up existing placeholder titles; this only stops new ones from being created.
• Admins can still overwrite the "Certificate Title" in the CMS.

Change

cms/api.py — create_default_certificate_page:

cert_page = CertificatePage(
    product_name=courseware.title,
    CEUs=f"PLACEHOLDER - {courseware.title} CEUs",
)

How to test

Automated:

docker compose run --rm web uv run pytest cms/api_test.py::test_create_default_certificate_page_defaults_to_title

• test_create_default_certificate_page_defaults_to_title (new) asserts a newly created certificate page's product_name equals the courseware title and contains no PLACEHOLDER text.

Manual (optional): create a new courseware page via create_courseware and confirm the generated certificate page's "Certificate Title" is the courseware title rather than PLACEHOLDER - … Certificate.

[github-actions]

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