/**
 * CogmemAi local SQLite database — schema, initialization, and query helpers.
 */
import Database from 'better-sqlite3';
/**
 * Get or create the SQLite database connection.
 */
export declare function getDb(): Database.Database;
/**
 * Close the database connection.
 */
export declare function closeDb(): void;
/**
 * Sync a memory row to the FTS5 index. Safe to call even if FTS5 is unavailable.
 */
export declare function ftsUpsert(id: number, subject: string, content: string, category: string, tags: string): void;
/**
 * Remove a memory from the FTS5 index. Safe to call even if FTS5 is unavailable.
 */
export declare function ftsDelete(id: number): void;
/**
 * Search the FTS5 index. Returns row IDs ranked by relevance, or null if FTS5 unavailable.
 */
export declare function ftsSearch(query: string, limit: number): Array<{
    id: number;
    rank: number;
}> | null;
/**
 * Compute expires_at from a TTL string like "7d", "24h", "30d".
 */
export declare function computeExpiresAt(ttl: string): string | null;