/**
 * Git branch detection and name sanitization.
 */
/**
 * Check if the current directory (or given path) is inside a git repository.
 */
export declare function isGitRepo(cwd?: string): Promise<boolean>;
/**
 * Get the root directory of the git repository.
 * Throws NotGitRepoError if not in a git repo.
 */
export declare function getRepoRoot(cwd?: string): Promise<string>;
/**
 * Get the current branch name.
 * Throws NotGitRepoError if not in a git repo.
 * Throws DetachedHeadError if in detached HEAD state.
 */
export declare function getCurrentBranch(cwd?: string): Promise<string>;
/**
 * Get the previous branch (the one checked out before the current one).
 * Returns null if there's no previous branch info.
 */
export declare function getPreviousBranch(cwd?: string): Promise<string | null>;
/**
 * List all local branches.
 */
export declare function listBranches(cwd?: string): Promise<string[]>;
/**
 * Sanitize a branch name for use as a filename.
 *
 * - Prevents path traversal (../, ~, leading /)
 * - Replaces non-alphanumeric chars (except . _ -) with _
 * - Collapses consecutive underscores
 * - Prevents leading dots (hidden files)
 * - Enforces max length of 200 characters
 */
export declare function sanitizeBranchName(branchName: string): string;
/**
 * Validate that a branch name is safe to use.
 * Returns an error message if invalid, null if valid.
 */
export declare function validateBranchInput(input: string): string | null;