Gate12A anchor-rich closure tension observable surface: transcript_v1 + briefing_v1 first replication checkpoint

This deposit records the first replication checkpoint for the Gate12A anchor-rich closure tension observable surface in pale-ale. The checkpoint is intentionally scoped. It does not claim a universal law, a threshold doctrine, or a global correctness classifier. Instead, it fixes a reproducible observable surface and the first cross-family comparison over two rendering families: transcript_v1 and briefing_v1. The tracked memo line recorded here establishes the following scoped empirical facts under the current Gate12A observable surface. In both families, zero-overlap transport collapse did not appear (`zero_overlap_count = 0`), all currently defined triangles were anchor-rich, and the directional subregime ordering remained stable (`residual_chord` flatter than `trusted_tree`, `anchor_qualified` flatter than `plain`). At the same time, first-pass phenotype mixtures shifted by family, and high residual did not behave as an immediate failure signal. This supports a narrow non-monotonic reading of closure tension at the observable-surface level while explicitly withholding any family-independent threshold claim. The deposit therefore fixes:1. the exact tracked memo set for Gate12A empirical scope through the first cross-family comparison,2. the committed-code run artifacts needed to inspect the current observable surface on transcript_v1 and briefing_v1,3. the first-pass reading surfaces used for the current extreme-band comparison. This is a replication checkpoint, not a final theory of LLM closure quality. Its purpose is to preserve a timestamped empirical surface that can be replicated, challenged, or extended by later families and later Gate12 lines.