backfill materials columns for recommendation table

src/app/db/migrations/0225_recommendation_material_id_backfill.sql

@@ -0,0 +1,26 @@
+-- Guard: fail if any recommendation maps to more than one material row.
+-- The modelled fabric measures never produce this; if real data violates it
+-- the backfill cannot pick deterministically and must not proceed silently.
+DO $$
+BEGIN
+  IF EXISTS (
+    SELECT 1
+    FROM   recommendation_materials
+    GROUP  BY recommendation_id
+    HAVING count(*) > 1
+  ) THEN
+    RAISE EXCEPTION
+      'recommendation_material_id backfill aborted: one or more recommendations '
+      'have multiple recommendation_materials rows. Resolve cardinality before re-running.';
+  END IF;
+END $$;
+
+-- Backfill all four columns in a single pass.
+UPDATE recommendation r
+SET    material_id            = rm.material_id,
+       material_quantity      = rm.quantity,
+       material_quantity_unit = rm.quantity_unit,
+       material_depth         = rm.depth
+FROM   recommendation_materials rm
+WHERE  rm.recommendation_id = r.id
+  AND  r.material_id IS NULL;

src/app/db/migrations/meta/_journal.json

@@ -1569,6 +1569,13 @@
       "when": 1780653770494,
       "tag": "0224_busy_nitro",
       "breakpoints": true
+    },
+    {
+      "idx": 225,
+      "version": "7",
+      "when": 1780654800000,
+      "tag": "0225_recommendation_material_id_backfill",
+      "breakpoints": true
     }
   ]
 }