import { type ExtractionProvenance } from './types.js';
export declare const INGEST_PROVENANCE_STAGE = "ingest";
/**
 * Normalize a metadata string by trimming whitespace and rejecting non-string or empty values.
 */
export declare function normalizeMetadataString(value: unknown): string | null;
/**
 * Derive structured ingest provenance from flat capture metadata such as `source_url` and `captured_at`.
 *
 * This keeps on-disk frontmatter backward-compatible while allowing extraction and normalization
 * to share one capability-resolution path for ingest provenance.
 */
export declare function deriveIngestProvenanceFromRecord(record: Record<string, unknown>, options?: {
    allowVirtual?: boolean;
}): ExtractionProvenance | null;
/**
 * Append derived provenance to an existing provenance list without mutating the input array.
 * Duplicate derived records are skipped by a stable provenance key.
 */
export declare function appendDerivedProvenance(records: readonly ExtractionProvenance[], derivedProvenance: ExtractionProvenance | null): ExtractionProvenance[];