/**
 * Project-root resolution shared by the three `peaks retrospective`
 * subcommands — hoisted VERBATIM from `retrospective-commands.ts`, where
 * the same four-line expression was written out three times (search,
 * index, show). Same branch order, same predicates: an explicit
 * `--project` is canonicalised, otherwise the discovered project root,
 * otherwise cwd.
 */
export declare function resolveRetrospectiveProjectRoot(project: string | undefined): string;