Bug: Media selection in content blocks doesn’t persist after save

[bobbwal]

Problem

In code‑based content blocks (e.g. Hero), selecting a media item appears to work, but the selection is lost after saving and revisiting the content.

Expected

Media selections inside block/object fields persist after save and reload.

Repro

1. Open Page Blocks → create new content.
2. Add a Hero block.
3. Select an image for image (media field).
4. Save and reopen the content.
5. Image is no longer selected.

Notes

Likely missing change events when media selection updates the hidden input, so structured fields don’t sync their JSON.