cad/openvsp: Update to 3.52.0

ChangeLog:
https://openvsp.org/blogs/announcements/2026/09/19/openvsp-3-52-0-released

Features:

• FitModel undo button
• FitModel GUI improvements
• FitModel API access
• Read point clouds as .csv files
• Read unformatted Plot3D and Cart3D .tri files
• Expose Parasite Drag flow conditions in Results – thanks Ojasvi

Bugs:

• Fix ID remapping when referencing an ID outside of the DecodeXml set
• Fix scaling of Reynolds number in VSPAERO
• Fix Mass Properties calculation – now better and faster
• API access to lights, control surface groups and FEA assembly connections
• AddMaterial now writes the material to the file
• Tag file names carry a . separator; CFDMesh writes them to a subdirectory
• Fix Parm lookup by container, name and group after a file load
• Fix NGonMesh contributing nothing to CompGeom and mass properties
• Fix WireGeom not moving when the Geom moves
• Fix WireGeom’s four patch types sharing one Parm name
• Fix VSPAERO control surface lookup for a Geom name containing an underscore
• Fix export crash on a model with no geometry
• Fix crashes and bad geometry from degenerate plates and zero area triangles
• Fix a polygon mesh being used after the sweep that deletes it
• Fix vspgeom key file dropping a part covered entirely by subsurfaces
• Fix Cobra exiting on a zero nose or aft length
• Fix Geom rename not reaching the rest of the model
• Register three GUI screen enums and the Background3D error code for scripts
• Fix the ‘N’ attachment buttons being outside the layout
• Fix colour picker deactivation