/**
 * Git helpers for compound extraction.
 *
 * Extracted from compound-extractor.ts — pure functions that shell out to git
 * for commit/diff data. All use execFileSync to prevent shell injection.
 */
/** Validate that a string is a valid git SHA (7-64 hex chars) */
export declare function isValidSha(sha: string): boolean;
/** Get new commits since last extraction */
export declare function getNewCommits(cwd: string, lastSha: string): string;
/** Get commit messages for "why" context enrichment */
export declare function getCommitMessages(cwd: string, lastSha: string): string;
/** Get git diff for extraction */
export declare function getGitDiff(cwd: string, lastSha: string): string;
/** Get diff stats for Gate 0 */
export declare function getDiffStats(cwd: string, lastSha: string): {
    files: number;
    lines: number;
    hasCodeFiles: boolean;
};