{
  "packet_id": "erhu-prototype-qianjin-scale",
  "instrument": "erhu-inspired two-string vertical fiddle",
  "issue": "https://github.com/tonykoop/instrument-maker/issues/150",
  "repo_issue": "https://github.com/tonykoop/erhu/issues/1",
  "readiness": "L2 V5 build-packet candidate",
  "readiness_level": "L2",
  "active_geometry": {
    "dimension_basis": "qianjin-to-bridge speaking length",
    "nominal_mm": 400,
    "setup_range_mm": {
      "min": 380,
      "max": 420
    }
  },
  "fabrication_authority": {
    "current_authority": [
      "cad/erhu-qianjin-scale-params.csv",
      "drawings/erhu-qianjin-scale-starter.dxf"
    ],
    "authority_scope": "qianjin-to-bridge setup strip only",
    "generated_images_authority": false
  },
  "v5_artifacts": {
    "mcp_provenance": "cad/mcp-session-log.md",
    "visual_authority_register": "visual-output-register.csv",
    "validation_loop": "validation-loop.csv",
    "qianjin_measurement_plan": "qianjin-measurement-plan.md",
    "resonator_photo_measurement_evidence": "resonator-photo-measurement-evidence.csv",
    "membrane_bridge_contact_capture": "membrane-bridge-contact-capture.csv",
    "resonator_authority_gates": "resonator-authority-gates.csv",
    "string_source_assumptions": "string-source-assumptions.csv",
    "risk_register": "risks.md",
    "wolfram_status": "source-only notes; no runtime execution claimed"
  },
  "uncertainties": [
    "membrane material and tension",
    "bridge height, mass, and foot geometry",
    "string set gauge and tension",
    "resonator body geometry",
    "qianjin placement details beyond speaking-length span"
  ],
  "validation_gates": "validation.csv"
}