Stopping a fill only requests cancellation; its worker keeps reading
Plate.Parts until it returns. The progress window is modeless, so a
click or key on the plate view in that window (clone placement, Delete,
arrow nudges, drops) changed the part list mid-enumeration and threw
"Collection was modified" in PlateFillService.TryAddClear.
PlateView now refuses editing input while IsFillInProgress, the same
way it does during an inspection. Panning and zooming stay live.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ajandClaude Opus 5.5
a10e204268