A user can connect several sources (GitHub, GitHub Enterprise, GitLab, Gitea/Forgejo) and every repository remembers which source it came from. New sources table (migration 0019) with repositories.source_id backfilled by provider and host, per-user unique indexes widened to include the source, a Sources card on the Configuration page with per-source lock confirmations, and credentials resolved from each repository's own source in discovery, import, scheduling, organization mirror, retry, recovery, push targets, cleanup and reconcile. The legacy githubConfig connection fields mirror the primary source so scripts and env setups keep working.
