* Render a paint from its Graphic directly instead of a single-element List wrapper
* Fix a stale doc comment reference to the moved paint render implementation
* Let the Fill and Stroke paint inputs take Item<Graphic>, replacing the IntoPaint trait
* Rename the FIll node's "fill" input to "paint"
* Let the graphic-consuming nodes take List<Graphic> directly, relying on the embedding adapters
* Remove outdated todo comments
* Re-save the demo art
* Split 'To Graphic' and 'Wrap Graphic' into the 'As Graphic' type assertion and 'Into Group' reducer nodes
* Make 'Into Group' reduce List<DVec2> not Item<DVec2>
* Reset the Merge definition for every legacy alias of its coercion nodes
* Improve test
* Add the rank-0 Item leaf variants to the Graphic enum, rendering leaves and list rows through shared per-row logic
* Traverse the rank-0 Graphic leaf variants in the vector node helpers and flattening
* Reach rank-0 vector graphics from the styling and gradient-fitting helpers
* Two code review fixes
* Fix comment
* Make the Artboard and Gradient newtype fields public to match the other list newtypes
* Rename the Graphic enum's self-named Graphic::Graphic variant to Graphic::GraphicList
* Rename the Graphic::Vector variant to Graphic::VectorList
* Rename the Graphic::RasterCPU variant to Graphic::RasterCPUList
* Rename the Graphic::RasterGPU variant to Graphic::RasterGPUList
* Rename the Graphic::Color variant to Graphic::ColorList
* Rename the Graphic::Gradient variant to Graphic::GradientList
* Rename the Graphic::Text variant to Graphic::TextList
* Restore the SVG group tag comment that the variant rename sweep clobbered
* Add the appearance model types and attribute constants
* Dual-write the appearance attribute alongside the fill/stroke pair in all paint-writing nodes
* Read paint from the appearance attribute in the renderer, analysis, metadata, and editor, cascading from ancestors
* Retire the fill/stroke attribute pair and the Vector stroke field in favor of the appearance attribute
* Replace the Stroke node's paint order input with the relative chain order of the Fill and Stroke nodes
* Code review fixes
* Re-save demo art
* Stamp coverages in place and fuse the renderer's per-item appearance reads into single walks
* Treat an empty appearance as the undeclared state so padded rows inherit instead of blocking the cascade
* Update demo art
* Treat padded appearance rows as undeclared in the boolean flatten's group recursion
