fix(problem-statement): admin-created statements attributed to muLearn, not a company

[afifshowfeer]

Admin could previously create a problem statement attributed to any company via company_id. Admin-created statements are now unattached to any company (company nullable, new source field) and are displayed as muLearn everywhere the statement is serialized (admin list, learner feed). Company-created statements are unaffected.

[greptile-apps]

Confidence Score: 4/5

[Medium impact] Changes how admin-created problem statements are stored and displayed.

The PR needs the matching database changes before merging.

Findings

1.  Database changes are missing ▶

Summary

Admin-created problem statements now belong to muLearn rather than a company.

• Admin-created statements belong to muLearn, not a company.
• MuLearn statements show muLearn in the company field.
• Searching “mulearn” finds muLearn statements in both lists.

_{Reviews (2) · Last reviewed commit: "test(problem-statement): replace admin-c..." · Reviewed by Greptile}

[greptile-apps]

Database changes are missing

ProblemStatement now requires source and allows a null company, but schema.sql has no source column and still requires company_id. With managed = False, Django will not change this table. If the database matches the checked-in schema, statement reads and writes fail with an unknown-column error. Admin creation also needs nullable company_id.

The repository rules require matching schema artifacts. Update schema.sql and add an upgrade script that supplies a default or backfill for existing rows.