/**
 * Derives a filesystem-safe path segment for a dev branch, used to namespace
 * on-disk artifacts (lock files, the `.trigger/tmp` build tree, watchdog state)
 * so concurrent `trigger dev` sessions on different branches in the same project
 * don't clobber each other.
 *
 * Returns `undefined` for the default branch (or no branch) so callers keep
 * their original, branch-less paths for backwards compatibility.
 */
export declare function devBranchPathSegment(branch?: string): string | undefined;