Federation (JSON) tracks an ordered list of model sources plus an
optional home-view camera state. Sources are stored relative when
under the federation file's directory, absolute otherwise.
File menu now exposes New / Open / Save / Save As; Add Files moves
to Ctrl+Shift+O. View menu gains Set/Go to Home View. Window title
binds to dirty state via setWindowModified, and the close-window
prompt offers Save/Discard/Cancel.
Per-model transform (4x4 column-major) and visible round-trip
through load/save but are not yet applied at the viewport — the
georeferencing work uses them.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Dion Moult