Generate a FreeCAD library of equipment envelopes at exact datasheet
dimensions with real masses attached as properties (each Victron box,
the Fronius, one US3000C and the 4-unit bank, the LONGi panel), so
layout studies and centre-of-gravity checks use true volumes from day
one. Third-party STEP models get a gitignored lib/ folder with a
tracked index, mirroring the constructor-doc pattern.
L'électron rare