Revision advanced by GCP, model or working-CRS changes.
Exactly the alignment revision explicitly confirmed by the user, or null when unconfirmed.
Monotonically increasing revision for all committed edits, including undo and redo.
Revision of the geographic feature draft.
Geographic drafts in longitude/latitude; re-alignment never moves these coordinates.
Alignment revision against which the geographic drawings were reviewed, or null when review is required.
Control-point pairs, including disabled pairs retained for editing and interchange.
Stable document ID and the scope for host feature replacement/deletions.
Selected transformation model; invalid fits never fall back to another model.
Settings for raster export; no raster export is required to persist features.
Source image and alignment provenance indexed by the corresponding feature ID.
Session format version; unknown versions are rejected by parseSession.
Source identity, or null when no image is selected.
CRS used for fitting, residuals and overlay preview; does not imply the map-view or output CRS.
Versioned, JSON-serializable editor document. Use controller methods to change its frozen snapshots; files, map objects and buffers are kept separately.