[12.x] Add --json option to ScheduleListCommand

[dxnter]

Summary

This PR adds a --json flag to the schedule:list command to allow programmatic consumption of scheduled task data for monitoring and integration purposes. This is implemented in a way that aligns with other Laravel commands like route:list, model:show, event:list, and db:table.

JSON Output

[
  {
    "expression": "0 0 15 * *",
    "repeat_seconds": null,
    "command": "php artisan backup:run",
    "description": "Run daily backup process",
    "next_due_date": "2025-09-15 00:00:00 +00:00",
    "next_due_date_human": "5 days from now",
    "timezone": "UTC",
    "has_mutex": false
  }
]

Example Use Cases

• Validate schedules after deployment
  • php artisan schedule:list --json | jq 'length'
• Monitor critical tasks
  • php artisan schedule:list --json | jq '.[] | select(.command | contains("backup"))'
• Transparency into automated processes in a user-friendly interface

  • $output = Artisan::call('schedule:list', ['--json' => true]);
    $schedules = json_decode(Artisan::output(), true);
    return view('admin.schedules', compact('schedules'));

  • @foreach($schedules as $schedule)
        <tr>
            <td>{{ $schedule['command'] }}</td>
            <td><code>{{ $schedule['expression'] }}</code></td>
            <td>{{ $schedule['next_due_date_human'] }}</td>
        </tr>
    @endforeach