Continues the Manual Alignment work: refines the FFT cross-correlation and
mask handling, adds sras_edit_scans.py (drop/renumber bad angle scans),
tools/test_alignment.py (registration ground-truth suite), and a rotating
test fixture in make_test_sras.py.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Thomas Ales