Front matter

. The working designation is XVIII-A, version 2. The supplied companion separately identifies XVII-A as a finite-matrix AdS${}_2$ reconstruction benchmark CheungRegisteredXVIIA. The present manuscript neither replaces that sheet nor imports its reconstruction maps. The designation here does not assert registration or authorization of authorship.

status. Every unconditional mathematical result below is proved from its printed definitions. Every conditional application states its hypotheses explicitly. A source record, comparison, continuation, or quoted stopping rule is not an independently verified theorem premise. An unconstructed object is described as unresolved, not as universally nonexistent.