docs: def schema():
      """
      All tables, columns, steps, injectables and broadcasts registered with
      Orca. Includes local columns on tables.
  
      """
      tables = orca.list_tables()
      cols = {t: orca.get_table(t).columns for t in tables}
      steps = orca.list_steps()
      injectables = orca.list_injectables()
      broadcasts = orca.list_broadcasts()
  
      return jsonify(
          tables=tables, columns=cols, steps=steps, injectables=injectables,
          broadcasts=broadcasts)