feat: sync latest ARR implementation

database/011_artifact_object_identity.sql

@@ -0,0 +1,42 @@
+-- Preserve one artifact row per immutable storage object identity.
+-- PostgreSQL 15+. Migrations 008-010 remain immutable.
+
+BEGIN;
+
+DO $$
+BEGIN
+    IF current_database() <> 'booking_test' THEN
+        RAISE EXCEPTION
+            'ARR artifact identity migration is allowed only in booking_test';
+    END IF;
+    IF to_regclass('ingestion.artifacts') IS NULL
+       OR to_regclass('ingestion.result_submissions') IS NULL THEN
+        RAISE EXCEPTION
+            'ARR migrations 008 through 010 must be applied first';
+    END IF;
+    IF NOT EXISTS (
+        SELECT 1
+        FROM pg_constraint
+        WHERE conrelid = 'ingestion.artifacts'::regclass
+          AND conname = 'artifacts_kind_hash_unique'
+    ) THEN
+        RAISE EXCEPTION
+            'ARR artifact identity migration is already applied or the source schema is invalid';
+    END IF;
+    IF to_regclass('ingestion.artifacts_kind_hash_idx') IS NOT NULL THEN
+        RAISE EXCEPTION
+            'ARR artifact identity lookup index already exists';
+    END IF;
+END;
+$$;
+
+ALTER TABLE ingestion.artifacts
+    DROP CONSTRAINT artifacts_kind_hash_unique;
+
+CREATE INDEX artifacts_kind_hash_idx
+    ON ingestion.artifacts (artifact_kind, sha256);
+
+COMMENT ON INDEX ingestion.artifacts_kind_hash_idx IS
+  'Non-unique content lookup. Equal bytes may belong to different immutable OSS object identities and processing runs.';
+
+COMMIT;