feat(ql3): establish 3.0 incubation baseline

back/runtime/domain/localArtifactRetentionCheckpoint.ts

@@ -0,0 +1,35 @@
+import {
+  normalizeLocalArtifactRetentionCursor,
+  type LocalArtifactRetentionCursor,
+} from './localArtifactRetention';
+
+export interface LocalArtifactRetentionCheckpoint {
+  version: number;
+  cursor?: LocalArtifactRetentionCursor;
+}
+
+export function normalizeLocalArtifactRetentionCheckpoint(
+  value: LocalArtifactRetentionCheckpoint,
+): Readonly<LocalArtifactRetentionCheckpoint> {
+  if (!value || typeof value !== 'object' || Array.isArray(value)) {
+    throw new TypeError(
+      'Local Artifact retention checkpoint must be an object',
+    );
+  }
+  if (
+    !Number.isSafeInteger(value.version) ||
+    value.version < 0 ||
+    value.version >= Number.MAX_SAFE_INTEGER
+  ) {
+    throw new TypeError(
+      'Local Artifact retention checkpoint version is invalid',
+    );
+  }
+  const cursor = value.cursor
+    ? normalizeLocalArtifactRetentionCursor(value.cursor)
+    : undefined;
+  return Object.freeze({
+    version: value.version,
+    ...(cursor ? { cursor } : {}),
+  });
+}