Publish or un-publish a container tree

Publishes a container tree, or pulls it back for correction.

LIVE makes it visible in normal curriculum reads; DRAFT hides it there again. Applies to the root and everything beneath it. A live parent holding draft children would be incoherent, so status is set on a root and cascades.

While a tree is DRAFT its placement stays editable: you can re-attach it to a different program with PUT /{structureId}/owner, or re-nest it with PUT /{structureId}/parent. Once LIVE, both are refused until you set it back to DRAFT, which is also how a wrong attachment gets fixed without deleting anything.

Safe to un-publish: nothing in the assessment pipeline reads containers, so the effect is what callers see, not how applications are assessed.