export interface CanonicalLegacyUser {
    user: {
        id: string;
        email: string;
        name?: string;
        image?: string | null;
    };
    accounts: Array<{
        id: string;
        providerId: string;
        accountId: string;
    }>;
}
export declare function resolveCanonicalUserForLegacySession(email: string): Promise<CanonicalLegacyUser | null>;
/**
 * Backfill the canonical Better Auth user for a verified legacy session.
 *
 * Older OAuth sessions were keyed by email in the framework `sessions` table
 * before every deployment required a Better Auth `user` row. Keep the legacy
 * session as the authentication proof, and use Better Auth's adapter only to
 * create the missing canonical user. Do not invent a provider account: the
 * next provider sign-in owns that link.
 */
export declare function ensureCanonicalUserForLegacySession(email: string): Promise<boolean>;