SeerProjectRepository no longer has project or repository FK fields — they were removed by migration 0016_remove_old_fks (SafeRemoveField with MOVE_TO_PENDING removes the fields from the Django model state). The current model in src/sentry/seer/models/project_repository.py only declares the project_repository FK to sentry.ProjectRepository.

However, the new endpoints and helpers introduced in this PR repeatedly reference the removed fields:

• src/sentry/seer/endpoints/project_seer_repos.py:
  • _get_project_repos_queryset (≈ line 132): SeerProjectRepository.objects.filter(project=project, repository__status=ObjectStatus.ACTIVE).select_related("repository") and annotation Replace("repository__provider", ...).
  • _serialize_project_repo (≈ line 67): project_repo.repository attribute access.
  • _get_project_repo / OrganizationSeerProjectRepoDetailsEndpoint.delete (≈ line 332): .filter(project=project, repository_id=repo_id, repository__status=...).
• src/sentry/seer/autofix/utils.py:
  • add_seer_project_repos (≈ line 891): .filter(project=project, repository_id__in=repo_ids) and SeerProjectRepository.objects.create(project=project, repository_id=...).
  • replace_all_seer_project_repos (≈ line 916): .filter(project=project).delete() and .create(project=project, repository_id=...).

Existing working code (e.g. read_preference_from_sentry_db, has_project_connected_repos) correctly traverses project_repository__project=... and project_repository__repository__status=.... The new endpoints/helpers will raise django.core.exceptions.FieldError: Cannot resolve keyword 'project' into field (and repository) on every GET/POST/PUT/DELETE, and _serialize_project_repo will additionally raise AttributeError because repository is no longer a direct relation.

Fix: replace project=project with project_repository__project=project, repository_id=.../repository_id__in=... with project_repository__repository_id=.../__in=..., repository__status=... with project_repository__repository__status=..., repository__provider/repository__name with project_repository__repository__provider/__name, and access project_repo.project_repository.repository in _serialize_project_repo. For create/delete, construct/select via the ProjectRepository link (e.g. look up or create the ProjectRepository row and pass project_repository=<pr>).

Also found at:

• src/sentry/seer/endpoints/project_seer_repos.py:250-282

The connected_ids duplicate check (lines 895–901) is performed before the transaction begins, so two concurrent requests for the same project+repo IDs can both pass the check; the second SeerProjectRepository.objects.create() then violates the unique constraint and raises an unhandled IntegrityError (500). Move the check inside the transaction after select_for_update.