export interface ThreadReferenceCopyTarget {  readonly kind: "pull-request" | "thread";  readonly value: string;  readonly clipboardTarget: string;  readonly successTitle: string;  readonly failureTitle: string;} export function resolveThreadReferenceCopyTarget(input: {  readonly threadId: string;  /** Undefined means no PR panel; null means its URL is not available yet. */  readonly openPanelPullRequestUrl?: string | null | undefined;  readonly linkedPullRequestUrl?: string | null;}): ThreadReferenceCopyTarget | null {  if (input.openPanelPullRequestUrl === null) return null;  const pullRequestUrl = input.openPanelPullRequestUrl ?? input.linkedPullRequestUrl;  return pullRequestUrl    ? {        kind: "pull-request",        value: pullRequestUrl,        clipboardTarget: "pull request link",        successTitle: "PR link copied",        failureTitle: "Failed to copy PR link",      }    : {        kind: "thread",        value: input.threadId,        clipboardTarget: "thread ID",        successTitle: "Thread ID copied",        failureTitle: "Failed to copy thread ID",      };}