Show the stored asset environment in ImageKit asset rows on the shared asset administration page

Problem/Motivation

The shared asset administration page in video_style is used to review tracked provider-managed video and poster assets across the site.

ImageKit asset rows can already store an owning environment marker such as prod or dev. That value matters operationally because remote actions such as synchronization and cleanup may be blocked when the stored asset environment does not match the current runtime environment.

The shared asset page should make that ownership visible. After the base module exposes an Environment column, the ImageKit provider needs to populate that column for its asset rows.

Steps to reproduce

1. Install video_style and video_style_imagekit.
2. Configure an ImageKit environment marker in settings.php.
3. Create or import tracked ImageKit asset rows that contain a stored environment marker.
4. Open /admin/config/media/video-styles/assets.
5. Observe that ImageKit asset rows do not currently display the stored environment in the table.

Proposed resolution

Update the ImageKit asset source so that each ImageKit asset row populates the shared Environment column using the stored asset environment value.

Expected behavior:

• If an ImageKit asset row has a stored environment marker, display it in the shared Environment column.
• If no environment marker is stored for a row, display an empty placeholder.
• Keep the environment ownership logic unchanged. This issue only surfaces existing metadata in the shared admin UI.

Remaining tasks

• Update the ImageKit asset source row builder to provide the shared environment table cell.
• Use the existing shared environment guard/helper to resolve the stored asset environment.
• Verify that ImageKit rows display the environment correctly on the shared asset administration page.

User interface changes

Yes.

ImageKit asset rows on the shared asset administration page will display their stored environment ownership in the new Environment column.

API changes

No.

This issue only changes provider-owned row output for the shared admin table.

Data model changes

No.

This issue only exposes already stored provider metadata in the UI.