/**
 * Tiny unified-diff helpers for human-readable doctor output.
 *
 * Wraps the `diff` package's createPatch into one call that returns a
 * pre-coloured unified diff (red = removed, green = added, dim = context).
 * Used by `agents doctor --diff`.
 */
export interface UnifiedDiffOptions {
    /** Number of context lines around each change (default: 3). */
    context?: number;
    /** Filename label shown in the patch header for the "expected" side. */
    fromLabel?: string;
    /** Filename label shown in the patch header for the "actual" side. */
    toLabel?: string;
}
/**
 * Build a unified-diff text comparing two strings. Returns an empty string
 * when contents are identical.
 */
export declare function unifiedDiff(expected: string, actual: string, options?: UnifiedDiffOptions): string;
/**
 * Colour a unified-diff string for terminal output. Indents each line with
 * a constant prefix so it nests cleanly under a header.
 */
export declare function colorizeUnifiedDiff(patch: string, indent?: string): string;
