The replay_feedback table was missing its foreign key constraint to
matches(match_id). This happened because CREATE TABLE IF NOT EXISTS
doesn't add FKs to existing tables.
Added an idempotent migration that checks for the constraint's existence
before adding it, ensuring it's safe to run on both fresh installs and
existing databases.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
b13f98416b