docs/planning/social.md US-5 (task 13). Models + Alembic migration only,
per the sibling-dependency boundary with the Groups API task.
- groups: id, name, description, owner_id (FK users, ON DELETE SET NULL --
a group is a durable multi-member community, so it and its full roster
survive the owner deleting their account; the API task handles surfacing
an ownerless group for reassignment).
- group_members: group_id/user_id (both FK, ON DELETE CASCADE -- pure
join-table rows with no meaning without either side), role
(owner/admin/member native enum, default member), joined_at, unique
constraint on (group_id, user_id).
- User gets owned_groups / group_memberships relationships.
- tests/conftest.py TEST_TABLES updated for truncation between tests.
- New tests/test_group_models.py: role assignment, unique-membership
rejection, group-delete cascade, member-delete cascade, and owner-delete
SET NULL survival -- all verified against real Postgres.
Verified: upgrade/downgrade/upgrade round-trip, \d-inspected schema matches
spec (FKs, cascade behavior, unique constraint, indexes), full backend
suite 166 passed / 0 regressions.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y2FESCaMXeJpC9gSctiEeD
