/**
 * Provider groups — single source of truth.
 *
 * Slash routing is always SAME-PROVIDER. Opus 5 → Haiku 4.5, Sol → Luna,
 * Grok 4.6 → 4.3, Gemini 3.1 Pro → 3.5 Flash-Lite. Never cross-provider.
 *
 * Order inside a group matters when two models share a price: the first
 * strictly-cheaper hit wins (findCheapestRoute / preflightRoute).
 */
export declare const PROVIDER_MODELS: Record<string, string[]>;
export declare function providerOf(model: string): string | null;