* feat(scene-graph)!: make a stroke a paint
Stroke extends Fill, so a stroke carries the same paint vocabulary a
fill does instead of a lone color. Every construction site now states
a solid paint type, which keeps today's behaviour exactly; rendering,
.fig conversion, and the stroke panel still read solid strokes only.
copyFill is generic over the paint shape so copyStroke reuses it
rather than repeating the deep copy of gradient stops, transforms and
pattern fields.
Groundwork for the gradient and image strokes in #797.
* test(scene-graph): cover a stroke's nested paint data in copyStroke
A stroke is a paint now, so its gradient stops and transform must copy
as deeply as a fill's; the fixture was solid and proved only the color
and dash pattern.
- Preserve parent-local movement during Control bypass
- Route native snapping menu actions through persisted preferences
- Harden guide alignment, lifecycle rendering, and transformed resize behavior
- Update preference descriptions and fractional position display
- Snap vector points, moved layers, and resized edges to geometry, objects, guides, and pixels
- Add persistent snapping preferences with browser and native menu controls
- Normalize canvas and layout guides across Scene Graph and .fig conversion
- Clear transient snapping feedback across interrupted interactions
