/**
 * Exit taxonomy for the materialised schema-gate container
 * (`@fjall/schema-gate`). The dependent app containers declare
 * `dependsOn: [{ container: "fjall-schema-gate", condition: "SUCCESS" }]`, so
 * ANY non-zero exit stops the task pre-RUNNING and counts toward the
 * deployment circuit breaker — the codes exist for the forensic log and the
 * deploy-time ECS tail, not for ECS itself.
 *
 * Lives in `@fjall/util` because three packages must agree on it: the gate
 * runner emits the codes, `@fjall/deploy-core`'s deployment tail translates
 * them into one human line, and the constructs' docs cite them. Coupled
 * values across package boundaries — a drift would have the tail describe
 * an exit the runner never emits.
 *
 * - `pass` (0) — every configured target verified; app containers start.
 * - `refused` (1) — a target's live schema does not satisfy the expected
 *   version (forward skew, or a never-migrated database). The gate did its
 *   job; the deploy must roll back or the migration must land first.
 * - `configError` (2) — the gate could not even attempt verification:
 *   missing/empty env, unsupported tool or engine family, or an internal
 *   error. Points at a construct bug or an author override.
 * - `connectionError` (3) — the server could not be reached after the
 *   bounded retry budget (network, TLS, timeout). Indeterminate: the schema
 *   may be fine.
 * - `busy` (4) — the server was reachable and answered every attempt, but
 *   refused to run the probe because a concurrency cap or quota was
 *   exhausted (ClickHouse `TOO_MANY_SIMULTANEOUS_QUERIES` 202 /
 *   `QUOTA_EXCEEDED` 201, Postgres `too_many_connections` 53300 /
 *   `cannot_connect_now` 57P03) for the whole budget. Indeterminate, and
 *   distinct from `connectionError` because the cure is different: the
 *   server is healthy and something else holds the slot.
 * - `denied` (5) — the server was reachable and rejected the gate's
 *   identity or its rights (auth failure, unknown user, missing grant,
 *   read-only violation). Definitive: no retry will change it, and the fix
 *   is provisioning, not capacity.
 *
 * Precedence when targets disagree: `configError` is detected before any
 * connection is attempted; then `refused` (definitive evidence), then
 * `denied` (definitive), then `busy`, then `connectionError` (both
 * indeterminate; `busy` carries the more specific cure).
 */
export declare const SCHEMA_GATE_EXIT: {
    readonly pass: 0;
    readonly refused: 1;
    readonly configError: 2;
    readonly connectionError: 3;
    readonly busy: 4;
    readonly denied: 5;
};
export type SchemaGateExitKind = keyof typeof SCHEMA_GATE_EXIT;
export type SchemaGateExitCode = (typeof SCHEMA_GATE_EXIT)[SchemaGateExitKind];
/**
 * One human line per exit kind, for the deploy-time ECS tail and forensic
 * logs. Keyed on the taxonomy so adding an exit kind without a hint is a
 * compile error (`Record<SchemaGateExitKind, string>` rejects a missing key).
 */
export declare const SCHEMA_GATE_EXIT_HINTS: Record<SchemaGateExitKind, string>;
/**
 * Inverse lookup for the deployment tail: an ECS container exit code → the
 * taxonomy kind, or `undefined` for a code the gate never emits (a signal
 * exit such as 143, or an OOM 137).
 */
export declare function schemaGateExitKind(code: number): SchemaGateExitKind | undefined;