.drawio (mxGraph XML) import v1 — the migration on-ramp from draw.io / diagrams.net. Reads plain <mxGraphModel> XML and the default compressed <mxfile> save (base64 → raw-deflate → URI-encoded). Vertices, styles, swimlane containers with real membership, and edges with labels all map onto the engine's own models — and every construct v1 drops is named in a warning, never lost in silence.