interface KokonutMRVPayload {
  farm_id: string;                  // Farm registry identifier
  timestamp: string;                // ISO 8601
  measurement_type: "ground" | "remote" | "community";

  // Ground sensing
  ground?: {
    volumetric_water_content: number; // % — moisture in soil volume
    electrical_conductivity: number;  // dS/m — salinity / nutrient proxy
    soil_temperature: number;         // °C
  };

  // Remote sensing
  remote?: {
    ndvi: number;    // general vegetation health
    reci: number;    // chlorophyll / nitrogen proxy
    ndre: number;    // dense or mature canopy monitoring
    msavi: number;   // early season / bare soil adjustment
    source: "landsat_8" | "sentinel" | "drone";
    image_url?: string; // IPFS CID or signed URL
  };

  // Community analytics
  community?: {
    crop_cycle_stage: string;
    plant_health_notes: string;
    water_analysis: string;
    soil_texture: string;
    disease_flags: string[];
  };

  // Attestation
  attested_by?: string;       // EAS attestation UID
  attestor_address?: string;  // Wallet that signed the attestation
}