CREATE TABLE IF NOT EXISTS ticket_attachments (
  id           TEXT PRIMARY KEY,
  ticket_id    TEXT NOT NULL REFERENCES tickets(id) ON DELETE CASCADE,
  project_id   TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
  filename     TEXT NOT NULL,
  content_type TEXT NOT NULL DEFAULT 'application/octet-stream',
  size_bytes   INTEGER NOT NULL,
  created_by   TEXT NOT NULL REFERENCES users(id),
  created_at   TEXT NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_attachments_ticket ON ticket_attachments(ticket_id);