/**
 * Self-update awareness for the connector.
 *
 * On startup the connector queries the npm registry for the latest
 * `jdcodec` version and compares against the version baked into this
 * build. If a newer version exists, the proxy emits a one-line warning
 * on stderr; the `doctor` subcommand surfaces the same finding as a
 * "warn" probe. The check is fire-and-forget — registry-down, no PATH
 * to npm, and timeout all degrade silently. We never block startup.
 *
 * Cache:
 *   - Successful lookups (any verdict — match or mismatch) cache the
 *     result for 24h at `~/.jdcodec/version-check.json` so repeated
 *     connector restarts don't hammer the registry. Cache is also
 *     written on a *failed* lookup with a short TTL (10 min) so a
 *     transient registry outage doesn't retry on every boot.
 *   - Cache directory mirrors the existing config-file location so
 *     the connector only ever touches one directory under the home dir.
 */
export declare const REGISTRY_URL = "https://registry.npmjs.org/jdcodec/latest";
export declare const PACKAGE_NAME = "jdcodec";
export type UpdateVerdict = {
    state: "current";
    current: string;
    latest: string;
} | {
    state: "outdated";
    current: string;
    latest: string;
} | {
    state: "unknown";
    current: string;
    reason: string;
};
export interface UpdateCheckIO {
    /** Defaults to globalThis.fetch. */
    fetchImpl?: typeof fetch;
    /** Defaults to `~/.jdcodec/version-check.json`. */
    cachePath?: string;
    /** Defaults to Date.now. */
    now?: () => number;
    /** Defaults to the package's own VERSION constant. */
    currentVersion?: string;
}
/**
 * Loose semver comparison sufficient for newer-than checks against
 * what npm publishes for this package. Avoids pulling in a semver
 * dependency for a single comparison point. Returns:
 *   -1 if a < b, 0 if a == b, 1 if a > b
 * Pre-release suffixes (e.g. -beta.1) compare lexicographically after
 * the numeric triple; this is a minor deviation from strict semver but
 * is correct for our publish discipline (we ship clean x.y.z bumps).
 */
export declare function compareVersions(a: string, b: string): number;
/**
 * Resolve the update verdict for the connector. Reads cache, queries the
 * registry if stale, writes cache, returns. Never throws — failures
 * become `state: "unknown"` verdicts with a human-readable reason.
 */
export declare function checkForUpdate(io?: UpdateCheckIO): Promise<UpdateVerdict>;
/** One-line human-readable summary suitable for a log line. */
export declare function formatVerdict(verdict: UpdateVerdict): string;