/**
 * COAIA Narrative - Perspective types of a narrative beat
 *
 * A narrative beat records one event as three perspectives read it: the engineer
 * perspective (structure and consequence), the ceremony perspective (relationship
 * and accountability) and the story_engine perspective (arc and meaning).
 *
 * Beats written before 0.17 stored this list under `metadata.universes` with the
 * values `engineer-world`, `ceremony-world` and `story-engine-world`. Those records
 * keep that key: the preservation check in jsonl-preservation.ts fails any rewrite
 * that drops a key a record already had. New beats are written with
 * `metadata.perspective_types` and the bare values. Every reader goes through
 * `readPerspectiveTypes`, so both forms read the same.
 *
 * Pure module: no I/O, no imports.
 */
export declare const PERSPECTIVE_TYPES: readonly ["engineer", "ceremony", "story_engine"];
export type PerspectiveType = (typeof PERSPECTIVE_TYPES)[number];
/**
 * Map one value to its stored form. Legacy `-world` values become the bare value.
 * Any other string passes through unchanged: the list has never been an enum, and
 * a caller's own value is not dropped.
 */
export declare function normalizePerspectiveType(value: string): string;
/** Normalize a list of values, dropping empty strings and repeats. */
export declare function normalizePerspectiveTypes(values: readonly unknown[]): string[];
/**
 * The perspective types of a stored beat. Reads `perspective_types` first and falls
 * back to the pre-0.17 `universes` key. Legacy `-world` values come back bare.
 */
export declare function readPerspectiveTypes(metadata: unknown): string[];