import type { AITierId } from '@donotdev/core/server';
/**
 * Resolve the AI model ID for a given tier.
 *
 * Resolution chain (first non-empty wins):
 * 1. `AI_MODEL_<FUNCTION_NAME>` env var (per-function override)
 * 2. `AI_TIER_<TIER>` env var (per-tier override)
 * 3. `AI_TIERS.<TIER>.defaultModel` (static SSOT from constants)
 *
 * @param tier - The tier ID ('fast', 'standard', 'premium')
 * @param functionName - Optional function name for per-function env var lookup
 * @returns The resolved model ID string
 */
export declare function resolveModelForTier(tier: AITierId, functionName?: string): string;
