/**
 * Normalizes an override URL by trimming whitespace.
 * Returns undefined for empty or whitespace-only strings.
 */
export declare function normalizeOverride(url?: string): string | undefined;
/**
 * Ensures a URL string ends with a trailing slash.
 * @remarks Used when constructing `new URL(path, baseUrl)` candidates.
 */
export declare function ensureTrailingSlash(value: string): string;
/**
 * Logs a warning when WASM fails to load from a URL and falls back to another.
 * @remarks This is intentionally a `console.warn` so host applications can filter logs if desired.
 */
export declare function logWasmFallbackWarning(url: string, error: unknown): void;
/**
 * Formats an error for display in error messages.
 * @remarks Avoids leaking non-Error objects into user-facing messages.
 */
export declare function formatError(error: unknown): string;
/**
 * Validates that a subId is within the valid range for batch invoices.
 * @throws Error if subId is not a valid integer within bounds.
 */
export declare function assertValidInvoiceSubId(subId: number): void;
/**
 * Converts a number or bigint to a safe JavaScript number.
 * @throws Error if the value is negative, not finite, or exceeds safe integer range.
 * @remarks This is used for WASM boundary values that must fit in JS number space.
 */
export declare function toSafeNumber(value: number | bigint, label: string): number;
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