/**
 * Normalize one optional CLI string flag by trimming whitespace and collapsing
 * empty strings to `undefined`.
 *
 * @param value Raw CLI value before normalization.
 * @returns The trimmed string when present, otherwise `undefined`.
 */
export declare function normalizeOptionalCliString(value?: string): string | undefined;
/**
 * Resolve one CLI path flag relative to the caller when it is expressed as a
 * local filesystem path.
 *
 * Non-local values such as npm package specs or `github:` locators pass
 * through unchanged. Local relative and absolute paths are resolved against the
 * provided `cwd` and must exist on disk.
 *
 * @param options Path resolution inputs for one CLI flag.
 * @param options.cwd Caller working directory used for relative path
 * resolution.
 * @param options.label Human-readable option label used in thrown errors.
 * @param options.value Raw CLI value before trimming and path resolution.
 * @returns The normalized string, or `undefined` when the option was omitted.
 * @throws When a local-looking path resolves to a missing filesystem entry.
 */
export declare function resolveLocalCliPathOption(options: {
    cwd: string;
    label: string;
    value?: string;
}): string | undefined;
/**
 * Validate the built-in template composition rule for external layers.
 *
 * @param options External layer CLI options after normalization.
 * @param options.externalLayerId Optional selected layer id.
 * @param options.externalLayerSource Optional layer source locator or path.
 * @throws When `externalLayerId` is provided without `externalLayerSource`.
 */
export declare function assertExternalLayerCompositionOptions(options: {
    externalLayerId?: string;
    externalLayerSource?: string;
}): void;
/**
 * Build the shared error message used when a built-in template receives a
 * `--variant` override.
 *
 * @param options Built-in template context.
 * @param options.templateId Built-in template id that rejected the variant.
 * @param options.variant User-supplied variant override.
 * @returns The canonical user-facing error message.
 */
export declare function createBuiltInVariantErrorMessage(options: {
    templateId: string;
    variant: string;
}): string;
/**
 * Reject unsupported `--variant` usage for built-in templates.
 *
 * @param options Built-in template validation context.
 * @param options.templateId Built-in template id being scaffolded.
 * @param options.variant Optional variant override from CLI flags.
 * @throws When a built-in template receives any explicit `--variant` value.
 */
export declare function assertBuiltInTemplateVariantAllowed(options: {
    templateId: string;
    variant?: string;
}): void;