import type { ThreadFeedEntry } from "../../lib/threadActivity";import type { QueuedThreadMessage } from "../../state/thread-outbox-model"; export type PendingThreadFeedEntry = ThreadFeedEntry & {  readonly pendingMessage?: QueuedThreadMessage;  readonly acknowledged?: boolean;}; /** Append the outbox after all presented activity, until the server echoes each message. */export function appendPendingThreadMessages(  presentedFeed: ReadonlyArray<ThreadFeedEntry>,  feed: ReadonlyArray<ThreadFeedEntry>,  queuedMessages: ReadonlyArray<QueuedThreadMessage>,): ReadonlyArray<PendingThreadFeedEntry> {  if (queuedMessages.length === 0) return presentedFeed;  const deliveredIds = new Set(    feed.flatMap((entry) => (entry.type === "message" ? [entry.message.id] : [])),  );  return [    ...presentedFeed,    ...queuedMessages      .filter((message) => !deliveredIds.has(message.messageId))      .map((pendingMessage): PendingThreadFeedEntry => ({        type: "message",        id: pendingMessage.messageId,        createdAt: pendingMessage.createdAt,        pendingMessage,        message: {          id: pendingMessage.messageId,          role: "user",          text: pendingMessage.text,          createdAt: pendingMessage.createdAt,          updatedAt: pendingMessage.createdAt,          turnId: null,          streaming: false,        },      })),  ];}