/**
 * Idempotently guarantee that a `.gitignore` in `directory` carries `entries`.
 *
 * Absent file → written with `header` followed by the entries, unless the
 * caller passes `createIfMissing: false`. Existing file → only the missing
 * entries are appended, under `marker` so the addition is attributable. An
 * entry already present anywhere in the file (at any indentation) is left
 * alone, so repeat calls are no-ops.
 *
 * `createIfMissing: false` is for migration callers, which append globs to a
 * checkout that already ignores something. Creating a `.gitignore` where the
 * author never had one is a write into their repository that they did not
 * ask for, and it is not what a migration means.
 *
 * Best-effort by design: this maintains repository hygiene, never correctness.
 * The caller's real work — writing config or recording deploy state — must not
 * fail because a `.gitignore` could not be written (read-only checkout, no
 * repository at all, permissions). Returns whether the file now provably
 * carries every entry, for callers that want to assert or log — so a skipped
 * creation reports `false`, because no file carries anything.
 */
export declare function ensureGitignoreEntries(directory: string, entries: readonly string[], options: {
    header?: string;
    marker: string;
    createIfMissing?: boolean;
}): boolean;