List approval requests

Example response

{
  "data": [
    {
      "id": "appr_abc123",
      "run_id": "run_xyz789",
      "session_id": "sess_def456",
      "tool_name": "execute_command",
      "tool_input": {
        "command": "rm -rf /tmp/test"
      },
      "comment": "Approved with caution"
    }
  ]
}