import type {  CheckpointId,  CheckpointRef,  CheckpointScopeId,  MessageId,  OrchestrationV2ThreadProjection,  RunId,} from "@t3tools/contracts";import * as DateTime from "effect/DateTime"; export interface ThreadCheckpointSummary {  readonly checkpointId?: CheckpointId;  readonly scopeId?: CheckpointScopeId;  readonly runId: RunId;  readonly checkpointTurnCount: number;  readonly checkpointRef: CheckpointRef;  readonly status: "ready" | "missing" | "error" | "stale";  readonly files: ReadonlyArray<{    readonly path: string;    readonly kind: string;    readonly additions: number;    readonly deletions: number;  }>;  readonly assistantMessageId: MessageId | null;  readonly completedAt: string;} /** Derives the checkpoint/diff rows needed by review UIs from native V2 entities. */export function deriveThreadCheckpointSummaries(  projection: OrchestrationV2ThreadProjection,): ReadonlyArray<ThreadCheckpointSummary> {  return projection.checkpoints.flatMap((checkpoint) => {    if (checkpoint.appRunOrdinal === null || checkpoint.runId === null) return [];    const assistantMessageId =      projection.messages.findLast(        (message) => message.runId === checkpoint.runId && message.role === "assistant",      )?.id ?? null;    return [      {        checkpointId: checkpoint.id,        scopeId: checkpoint.scopeId,        runId: checkpoint.runId,        checkpointTurnCount: checkpoint.appRunOrdinal,        checkpointRef: checkpoint.ref,        status: checkpoint.status,        files: checkpoint.files,        assistantMessageId,        completedAt: DateTime.formatIso(checkpoint.capturedAt),      },    ];  });}