Function diffEvidenceBundles

Returns {
    bundleA: {
        agentId: string;
        integrityIndex: number;
        overall: number;
        runId: string;
        trustLabel: string;
    };
    bundleB: {
        agentId: string;
        integrityIndex: number;
        overall: number;
        runId: string;
        trustLabel: string;
    };
    deltas: {
        integrityIndex: number;
        layer: { delta: number; layerName: string }[];
        overall: number;
    };
}