Add Visio (.vsdx/.vsd) import using libvisio-ng

Summary

Adds import support for Microsoft Visio files (.vsdx and .vsd) using libvisio-ng.

What it does

• Registers .vsdx (Visio 2013+ XML) and .vsd (Visio 97-2003 binary) as importable formats
• Converts Visio pages to SVG using libvisio-ng
• Page selection parameter included

Why libvisio-ng?

The C++ libvisio has been largely unmaintained. libvisio-ng is a pure-Python alternative supporting themes, gradients, shadows, hatching, connectors, master shapes, binary .vsd (NURBS, splines, embedded images, layers), and more. 102 tests, CI on Python 3.10-3.14.

Available on PyPI: pip install libvisio-ng

Links

• PyPI: https://pypi.org/project/libvisio-ng/
• Source: https://github.com/yeager/libvisio-ng
• Comparison with C++ libvisio: https://www.danielnylander.se/2026/02/28/libvisio-ng-modern-visio-parser/