Release criteria and copied prerequisites

The three endings apply to the named analytic construction:

1. Constructed: the joint distribution exists with the prescribed normalizations, the four successor obligations are discharged, and its pushed-forward coefficient is admitted.

2. Proved obstructed: a demonstrated incompatibility excludes every successful construction in a previously frozen class.

3. Unresolved: a required prescription, estimate, contact composition, or output theorem has not been established.

Failure of a sufficient product criterion is not the second ending. A constructed elementary extension is not a joint extension.