Persist exact workflow revisions additively

.github/workflows/ci.yml

@@ -697,6 +697,16 @@ jobs:
         env:
           DATABASE_URL: postgres://buzz:${{ env.BUZZ_TEST_POSTGRES_PASSWORD }}@localhost:5432/buzz
           TEST_DATABASE_URL: postgres://buzz:${{ env.BUZZ_TEST_POSTGRES_PASSWORD }}@localhost:5432/buzz
+      - name: Workflow revision rollout PostgreSQL tests
+        # Keep mixed-version invalidation and atomic rebinding in the permanent
+        # Postgres gate; these cases are ignored by infrastructure-free units.
+        run: |
+          cargo nextest run \
+            --archive-file target/ci/backend-integration-tests.tar.zst \
+            -E 'package(buzz-db) and test(/^store::workflow::/)' \
+            --run-ignored ignored-only
+        env:
+          BUZZ_TEST_DATABASE_URL: postgres://buzz:${{ env.BUZZ_TEST_POSTGRES_PASSWORD }}@localhost:5432/buzz
       - name: Database pressure observability PostgreSQL tests
         # Explicit pool acquisition and advisory-lock metrics require real
         # Postgres and are ignored by the infrastructure-free unit-test job.

crates/buzz-db/src/runtime/migration.rs

@@ -690,7 +690,7 @@ mod tests {
         let mut migrations: Vec<_> = MIGRATOR.iter().collect();
         migrations.sort_by_key(|migration| migration.version);
 
-        assert_eq!(migrations.len(), 40);
+        assert_eq!(migrations.len(), 41);
         assert_eq!(migrations[0].version, 1);
         assert_eq!(&*migrations[0].description, "initial schema");
         assert!(migrations[0]
@@ -1153,6 +1153,35 @@ mod tests {
         assert!(heartbeat_vacuum.contains("vacuum_truncate = false"));
         assert!(desired_schema.contains("vacuum_truncate = false"));
 
+        // Workflow revision capture is additive: nullable 32-byte event IDs on
+        // both the materialized definition and run, with identical fresh-schema
+        // constraints and no backfill hidden in startup migration state.
+        assert_eq!(migrations[40].version, 41);
+        let workflow_revision_binding = migrations[40].sql.as_str();
+        assert!(workflow_revision_binding.contains("ALTER TABLE workflows"));
+        assert!(workflow_revision_binding.contains("ALTER TABLE workflow_runs"));
+        assert!(workflow_revision_binding.contains("octet_length(definition_event_id) = 32"));
+        assert!(!workflow_revision_binding.contains("UPDATE workflows"));
+        let revision_guard = |sql: &str| {
+            let start = sql
+                .find("CREATE FUNCTION invalidate_workflow_revision()")
+                .unwrap();
+            let end = sql[start..]
+                .find("FOR EACH ROW EXECUTE FUNCTION invalidate_workflow_revision();")
+                .unwrap();
+            sql[start..start + end].to_owned()
+        };
+        assert_eq!(
+            revision_guard(workflow_revision_binding),
+            revision_guard(desired_schema)
+        );
+        assert_eq!(
+            desired_schema
+                .matches("octet_length(definition_event_id) = 32")
+                .count(),
+            2
+        );
+
         // pgschema intentionally reconciles DDL, not seed DML or table storage
         // parameters. Its post-apply reconciliation must restore and verify
         // both parts of the live heartbeat contract for fresh bootstraps.