Headlessly, grid/snap are stored on the active VPORT, CANNOSCALE in
AcDbVariableDictionary (+ an ACAD_SCALELIST entry), and LIMMIN/LIMMAX on
the model-space layout as well as the header — measured: the header alone
is overwritten at save. Registry-saved variables (AUTOSNAP, POLARANG, …)
are refused with capability registry_sysvar instead of vanishing.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
