/**
 * Beam Shield — Wall 3: Content Sandbox
 * Detects prompt injection, strips unsafe content, wraps in isolation frame.
 */
/** Normalize Unicode: NFC + strip zero-width chars + replace confusables */
export declare function normalizeUnicode(text: string): string;
export declare const INJECTION_PATTERNS: Array<{
    pattern: RegExp;
    name: string;
    severity: number;
}>;
export declare function stripHtmlAndMarkdown(text: string): string;
export declare function truncateMessage(text: string, maxLength?: number): string;
export interface SanitizeResult {
    sanitized: string;
    injectionDetected: boolean;
    riskScore: number;
    matchedPatterns: string[];
    severity: 'none' | 'low' | 'medium' | 'high' | 'critical';
}
export declare function sanitizeExternalMessage(message: string): SanitizeResult;
export interface SenderContext {
    beamId: string;
    trustScore: number;
    verificationTier: string;
}
export declare function wrapInIsolationFrame(message: string, sender: SenderContext): string;