- The exit overlay says which step of shutdown is running and what it waits on ("Stopping the OCR
scan: finishing the text lines it is reading.", the import, the viewer, the models), and how long
that step has taken once it passes 2 s. It said "Saving..." for all of it.
- OCR stops mid-batch: ocr_process takes a cancel flag (Ocr_Engine.cancel), checked by its workers
before each piece of work; a scan sets it to its own cancel. A cut-short batch stores nothing and
counts no failures. Closing during a scan took minutes when a batch held large images; now well
under a second.
- Once shutdown starts, the main thread stops running the app's frames (the viewer, search, import,
OCR, Stats) and draws only the overlay: background_frame read the search thread group while the
shutdown thread was tearing it down, an access violation on exit.