spacr.qt.screens.annotate
AnnotateScreen — Qt widget replacing the Tk AnnotateApp.
Displays a paginated grid of clickable image thumbnails backed by png_list in a measurements/measurements.db. Left-click = value 1, right-click = value 2, re-click the same value = clear. Annotations are persisted through a background SaveWorker (see spacr.qt.annotate_engine.SaveWorker).
Advanced features that are not yet ported (marked as TODOs in the UI): UMAP window, Deep Spacr training launcher, measurement-threshold filtering (the threshold filter can be entered in settings but only plain per-page fetch is used at query time in this MVP).