import type { ApprovedMissionModelSnapshot, StoredSnapshot } from "./types.js";
/** Current snapshot schema version. Only this version exists today. */
export declare const SNAPSHOT_SCHEMA_VERSION = "1.0.0";
/**
 * Deterministic serialization of a snapshot value. Object keys are
 * sorted, Maps are encoded as tagged entry lists sorted by key, and
 * undefined values are dropped (matching JSON storage semantics).
 */
export declare function canonicalizeSnapshot(value: unknown): string;
/**
 * Compute the content signature of a snapshot.
 *
 * The signature input is the snapshot's deterministic planning
 * content: identity, schema version, session binding, world model,
 * proposals, and the structural lineage fields (version, parentId,
 * approvedBy). Wall-clock approval metadata (timestamp, lineage
 * approvedAt, and the lineageId derived from them) is excluded so
 * that approving the same session twice yields the same signature.
 *
 * Lineage chaining: when the snapshot has a lineage parent, the
 * parent's signature must be supplied and is mixed into the
 * signature input, so a tampered ancestor invalidates descendants.
 */
export declare function signSnapshot(snapshot: ApprovedMissionModelSnapshot, parentSignature?: string): string;
/**
 * Certify a stored snapshot. Returns a list of violations;
 * an empty list means the snapshot is certified.
 *
 * Checks:
 *   - known schema version
 *   - required fields present and well-formed
 *   - stored session bound to the snapshot
 *   - proposal graph validity (EXP-HARDEN-001)
 *   - lineage structure consistent with the parent (when provided)
 *   - signature recomputation match (with lineage chaining)
 *
 * A snapshot with a lineage parent can only be certified when the
 * parent snapshot is supplied: the chain input is unverifiable
 * without it.
 */
export declare function certifySnapshot(stored: StoredSnapshot, parent?: ApprovedMissionModelSnapshot): string[];
/**
 * Load a stored snapshot record at a known schema version.
 *
 * Only version "1.0.0" exists today, so loading is the identity.
 * When a future version is introduced, this is the seam where
 * conversions from older versions are applied. Unknown or future
 * versions are rejected loudly.
 */
export declare function migrateStoredSnapshot(raw: StoredSnapshot): StoredSnapshot;