/**
 * [WHO]: DiagnosticBuffer, coerceDiagnosticEvent()
 * [FROM]: Depends on ./types.js and ./redaction.js for event schema and privacy normalization
 * [TO]: Consumed by extensions/builtin/diagnostics/index.ts
 * [HERE]: extensions/builtin/diagnostics/diagnostic-buffer.ts - session-local dedupe and prompt gating state
 */
import { type DiagnosticEvent, type DiagnosticRecord } from "./types.js";
export declare class DiagnosticBuffer {
    private records;
    add(event: DiagnosticEvent): DiagnosticRecord;
    all(): DiagnosticRecord[];
    last(): DiagnosticRecord | undefined;
    findPromptCandidate(): DiagnosticRecord | undefined;
    findUnreported(): DiagnosticRecord[];
    markPrompted(fingerprint: string): void;
    markReported(fingerprint: string): void;
    private trim;
}
export declare function coerceDiagnosticEvent(value: unknown): DiagnosticEvent | undefined;