create table audit_logs (
  id uuid primary key default gen_random_uuid(),
  actor_id uuid references users(id) on delete set null,
  action text not null check (char_length(action) between 1 and 120),
  subject_type text not null check (char_length(subject_type) between 1 and 80),
  subject_id uuid,
  metadata jsonb not null default '{}'::jsonb,
  ip_address inet,
  created_at timestamptz not null default now()
);

create index audit_logs_created_index on audit_logs (created_at desc);
create index audit_logs_actor_index on audit_logs (actor_id, created_at desc);