CogmapRegionMetricsRow

The per-region analytics tier (the five materialized scalar readouts) as returned by
cogmap_region_metrics. Sibling to CogmapRegionRow's surface tier; member identities are still
never carried. Each metric is Option<f64> (the columns are nullable until materialization computes
them; telos_alignment stays None when the telos has no embedded chunks).

{ "centrality": 0, "content_cohesion": 0, "internal_tension": 0, "lens_id": "a0bf70da-a7fe-4851-8b57-062b597df966", "reference_standing": 0, "region_id": "b85c353a-cf17-4085-995a-928552ce32d0", "telos_alignment": 0 }