7807eae957
- Admin "backfill all" and `wp tmdo post-migrate-group` take any registered post group via TMDO_Post_Migration::backfillable_groups() instead of a hard-coded list of 7 (dev36 registers 11; the 4 HP add-on groups were never backfilled). Restored orphan groups are excluded and rejected — their values live only in the flat table. - Groups with json fields (attachment, nav_menu_item) go row by row through the migration engine instead of leaving the json columns NULL in the bulk pivot. - Verify: PostBackfillJsonTest (3 RED on hardening/2.2); dev36 post-migrate-group attachment / nav_menu_item / hp_draft_flags: json columns semantically equal native (24/24, 21/21), checker unchanged. - PR: PR-067