forked from 1b-agent/opencadstudio-upstream
The Layer Manager only allowed one layer at a time. Now: - Ctrl/Cmd-click toggles a layer in the selection; Shift-click selects the range from the anchor; a plain click selects just one. - Colour, linetype and lineweight changes apply to every selected layer. - Delete removes all selected layers at once (reusing the #237 non-empty warning, now pluralised); layer "0" and the current layer are skipped. Selection is stored as row indices but re-resolved by name across sorts and layer-table rebuilds, so it never points at the wrong rows. Modifier state is tracked via a new SetModifiers message (shift + ctrl/cmd). Co-Authored-By: Claude Opus 4.8 <[email protected]>