c63a71883b
joinedload("reviewer") used a string instead of a class-bound
attribute (rejected by SQLAlchemy 2.x), and models.submission was the
wrong import path for Submission. Both endpoints 500'd whenever
actually called; surfaced while wiring real dashboard/activity data
into the frontend.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>