/**
 * Back-compat bridge: build a Partial<EnvironmentConfig> from the LOG10X_*
 * env-var vocabulary that pre-dates the env.json document.
 *
 * This is intentionally best-effort. The resolver decides whether the
 * resulting partial is complete enough to be accepted as a standalone fallback
 * (when no on-prem store has the env) — this file just packages the env vars
 * into the modern shape. Missing fields stay missing; nothing is fabricated.
 *
 * The recognized variables (each optional):
 *
 *   LOG10X_ENV_ID                — env_id
 *   LOG10X_ENV_NICKNAME          — nickname
 *
 *   LOG10X_CLUSTER_TYPE          — cluster.type
 *   LOG10X_CLUSTER_REGION        — cluster.region
 *   LOG10X_CLUSTER_ACCOUNT       — cluster.account
 *   LOG10X_CLUSTER_PROJECT_ID    — cluster.project_id
 *   LOG10X_CLUSTER_SUBSCRIPTION  — cluster.subscription
 *   LOG10X_CLUSTER_CONTEXT       — cluster.context_name
 *
 *   LOG10X_SIEM_VENDOR           — destination.siem_vendor
 *   LOG10X_SIEM_REGION           — destination.region
 *   LOG10X_SIEM_LOG_GROUP_PREFIX — destination.log_group_prefix
 *   LOG10X_SIEM_INGEST_URL       — destination.ingest_url
 *
 *   LOG10X_OFFLOAD_TYPE          — offload_destinations[0].type
 *   LOG10X_OFFLOAD_NICKNAME      — offload_destinations[0].nickname  (default "primary")
 *   LOG10X_OFFLOAD_BUCKET / LOG10X_STREAMER_BUCKET — offload_destinations[0].bucket
 *   LOG10X_OFFLOAD_PREFIX        — offload_destinations[0].prefix
 *   LOG10X_OFFLOAD_REGION        — offload_destinations[0].region
 *   LOG10X_OFFLOAD_PROJECT_ID    — offload_destinations[0].project_id
 *   LOG10X_OFFLOAD_STORAGE_ACCOUNT — offload_destinations[0].storage_account
 *   LOG10X_OFFLOAD_PATH          — offload_destinations[0].path
 *
 *   LOG10X_STREAMER_URL          — streamer.url
 *   LOG10X_STREAMER_TARGET_PATH  — streamer.target_path
 *
 *   LOG10X_RETRIEVER_URL         — retriever.url
 *   LOG10X_RETRIEVER_INPUT_BUCKET — retriever.input_bucket
 *   LOG10X_RETRIEVER_INPUT_PREFIX — retriever.input_prefix
 *   LOG10X_RETRIEVER_Q_INDEX     — retriever.query_queues.index
 *   LOG10X_RETRIEVER_Q_SUBQUERY  — retriever.query_queues.subquery
 *   LOG10X_RETRIEVER_Q_STREAM    — retriever.query_queues.stream
 *   LOG10X_RETRIEVER_Q_QUERY     — retriever.query_queues.query
 *   LOG10X_RETRIEVER_LOG_GROUP   — retriever.query_log_group
 *
 * Returns `null` when zero LOG10X_* variables are set — that signals the
 * resolver to skip the env-var path entirely rather than churn through an
 * empty partial.
 */
import type { EnvironmentConfig } from './types.js';
export declare function envConfigFromEnvVars(env?: NodeJS.ProcessEnv): Partial<EnvironmentConfig> | null;