New MCP tool `export_pcb_dxf` wrapping `kicad-cli pcb export dxf`: exposes the full layer-plot surface (layer/common-layer lists, refdes/value exclusion, soldermask subtraction, use-contours, use-drill-origin, border+title, output-units, the four DNP fab-layer modes, drill-shape, and the single/multi output modes). Reads the saved .kicad_pcb. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>