phsl / new-api

* Added migration logic in `controller/console_migrate.go`
  * Detects both `UptimeKumaUrl` and `UptimeKumaSlug`
  * Creates a single-group JSON array under `console_setting.uptime_kuma_groups`
    - Uses `categoryName: "old"` to mark migrated data
    - Preserves original `url` and `slug` values
  * Clears and removes obsolete `UptimeKumaUrl` and `UptimeKumaSlug` keys
* Removes outdated code paths that wrote to `console_setting.uptime_kuma_url` and `console_setting.uptime_kuma_slug`
* Keeps frontend `DashboardSetting.js` compatible — no additional changes required
* Aligns migration behavior with previous `ApiInfo` refactor for consistent console settings management