/**
 * Env Utilities — Shared helpers for reading and merging .env files.
 *
 * Consolidates the three scattered env-loading implementations:
 *   - MemoireEngine._loadEnvFile()
 *   - connect.ts findExistingEnvValue()
 *   - setup.ts readEnvValue()
 *
 * All functions are pure and safe to call from any command.
 */
/**
 * Read a single `.env`-style file and merge KEY=VALUE pairs into `process.env`.
 * Existing keys are never overwritten. Absent files are silently skipped.
 */
export declare function loadEnvFile(root: string, filename: string): Promise<void>;
/**
 * Load `.env.local` then `.env` from `root` into `process.env`.
 * Existing keys are never overwritten.
 */
export declare function loadEnvFiles(root: string): Promise<void>;
export type EnvSource = "process" | ".env.local" | ".env" | "missing";
export interface EnvValue {
    value: string | null;
    source: EnvSource;
}
/**
 * Find a config value by checking process.env first, then `.env.local` and `.env`
 * in the given project root. Returns the value and the source it was found in.
 */
export declare function readEnvValue(root: string, key: string): Promise<EnvValue>;
/**
 * Shorthand that returns only the value string (or null).
 * Use when you don't need the source metadata.
 */
export declare function readEnvValueRaw(root: string, key: string): Promise<string | null>;