multi tenancy part 1

backend/migrations/20240902011500_seed_admin_membership/up.sql

@@ -0,0 +1,7 @@
+INSERT INTO public.user_memberships (id, user_id, tenant_id, role)
+SELECT gen_random_uuid(), u.id, t.tenant_id, 'admin'
+FROM public.users AS u
+JOIN public.tenants AS t ON t.slug = 'admin'
+LEFT JOIN public.user_memberships AS um ON um.user_id = u.id AND um.tenant_id = t.tenant_id
+WHERE u.username = 'admin' AND um.id IS NULL
+ON CONFLICT (user_id, tenant_id) DO NOTHING;