feat(ql3): establish 3.0 incubation baseline

back/runtime/ports/localArtifactByteRangeReader.ts

@@ -0,0 +1,21 @@
+import type { LocalArtifactReadRange } from '../domain/artifactRead';
+
+export interface AvailableLocalArtifactByteRange {
+  status: 'available';
+  content: Buffer;
+  start: number;
+  endExclusive: number;
+  totalBytes: number;
+  nextOffset?: number;
+}
+
+export type LocalArtifactByteRangeReadResult =
+  | AvailableLocalArtifactByteRange
+  | { status: 'missing' };
+
+export interface LocalArtifactByteRangeReader {
+  read(
+    logArtifactId: string,
+    range: Readonly<LocalArtifactReadRange>,
+  ): Promise<LocalArtifactByteRangeReadResult>;
+}