Replace ~44 per-slot blocking device reads per poll with a single bulk
flomni_samples.read(), and add change-detection so cells only repaint
when their state actually changes. The old per-slot accessors stalled
the GUI event loop every 2s; steady-state polling now does no UI work.
Writes invalidate the changed slot's cache so local edits still repaint
immediately.
GUI for ftransfer_show / ftransfer_modify. Displays the
sample stage (0), gripper (100) and magazine slots 1-20 in a 4x5 grid
matching the CLI layout. Right-click per slot corrects the records
(new / rename / clear), each action confirmed by its own dialog and
written immediately. Bookkeeping only: writes flomni_samples directly
(mirroring flomni_modify_storage_non_interactive), never moves hardware.
Guarded on fsamroy; OMNY shows a not-implemented placeholder.