/**
 * v0.8.1 — `schema_version` backfill for bundled + workspace SKILL.md
 * frontmatter.
 *
 * Per docs/plan/v0.8.1-security-lifecycle-pair.md §6.3. Lives under `src/`
 * (not `scripts/`) because tsc only emits files under `bin/` + `src/` —
 * the 0.8.0 → 0.8.1 migration imports the same logic at runtime.
 *
 * Both the standalone CLI (`scripts/inject-skill-schema-version.ts`) and
 * the migration script call `injectAcross()`. The function is idempotent —
 * files that already carry `schema_version` are left byte-identical.
 */
export interface InjectResult {
    injected: string[];
    alreadyHad: string[];
    skipped: {
        file: string;
        reason: string;
    }[];
}
/** Walk a directory and return every SKILL.md found. */
export declare function listSkillFiles(root: string): string[];
/**
 * Inject `schema_version: <version>` into a frontmatter block. Returns the
 * new content, or null if the file already has the key. Throws on missing
 * frontmatter so the caller can flag the file as broken (rather than
 * silently mutating it).
 *
 * Preserves the original line endings (CRLF vs LF) so the round-trip
 * remains byte-identical for already-stamped files.
 */
export declare function injectSchemaVersion(content: string, version?: number): string | null;
/**
 * Walk a directory recursively and inject `schema_version: <version>` into
 * every SKILL.md file. Returns a structured report of injected / already-had
 * / skipped files.
 */
export declare function injectAcross(root: string, version?: number): InjectResult;