Refactor the 'Fill' and 'Stroke' nodes to set "fill" and "stroke" attributes for paints (#4257)

* Allow using any graphics type for fill

* Adapt gradient/fill property panels and tools to handle List<T>

* Make the initial gradient transform covers the target's bounding box

* Introduce AnyGraphicListDyn to avoid combinatorial explosion

* Allow using any graphics type for stroke paint

* Add FIll node migration

* Add `for_each_vector_list_mut` instead of `set_paint_attribute`

* Adapt paint flow to read and write attributes instead of legacy Fill/Stroke.color

* Fix responsibilities of paint related node input setters

* Fix Morph by storing List<Graphic> for attributes rather than the concrete types

Store fill/stroke paints as List<Graphic> so Color/Gradient transitions
do not hit set_attribute_value_dyn's type-mismatch fallback to default paint.

* Preserve paint attributes in vector editing ops

* Enhance the clarity between direct and chained fill gradients

* Update demo arts

* Consolidate Fill node gradient appearance inputs

* Fix after the cubic review

* Revert "Consolidate Fill node gradient appearance inputs"

This reverts commit 9622feb20196e2c4da99e98ca95dcc2e34c2c98e.

* Replace AnyGraphicListDyn with generic paint connectors on the Fill and Stroke nodes

* Canonicalize paint attribute storage to List<Graphic> with a single write helper

* Fix Solidify Stroke missing fills stored in the legacy style

* Fix Solidify Stroke producing invisible strokes for legacy-only stroke colors

* Fix the initial gradient transform ignoring the bounding box's vertical extent

* Step paint at the morph midpoint instead of dropping it for unmixable pairings

* Remove migration-stage comments

* Clarify the initial gradient transform helper's doc and name

* Correct the bake_paint_transforms doc and prune dead tolerance arms

* Delete the unused Gradient::lerp

* Fix a comment typo

* Thread network paths through the legacy gradient bake so nested fills migrate

* Restore the legacy fill fallback in Expand Fill and Stroke

* Read gradient stops from the node's own input in the Fill properties panel

* Use the transform input constant instead of a hardcoded index

* Remove the unreachable wired color fallback in the Fill properties solid branch

* Narrow the fill overlay redraw check to actual fill inputs

* Coalesce the fill setter's graph runs into a single dispatch

* Position the Gradient Value node inserted for gradient stops

* Bake backup gradient placement during migration

* Persist pending gradient bakes so unfinished migrations retry on reopen

* Migrate the backup gradient's type and spread method

* Harden the gradient-migration pass against document switches and stale bakes

* Keep the Fill properties UI for layerless and nested Fill nodes

* Leave a wired gradient transform input connected instead of overwriting it

* Refuse to start a gradient chain ahead of existing layer content

* Decode a Fill node's gradient through one shared reader

* Nudge a degenerate bounding box so the Fill gradient transform stays invertible

* Broadcast Fill and Stroke paint with a single attribute-column pass

* Fix Morph stepping the target's stroke in near the source instead of the target

* Tidy conventions: clippy get_first, comment periods, sentence-case test messages

* Reattach the gradient orientation doc to its function

* Re-save demo artwork

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

node-graph/nodes/graphic/src/artboard.rs

@@ -9,7 +9,7 @@ use vector_types::GradientStops;
 
 /// Constructs a single-element `Artboard[]` with the given content and metadata stored as row attributes.
 #[node_macro::node(category(""))]
-pub async fn create_artboard<T: IntoGraphicList + 'n>(
+pub async fn create_artboard<T: IntoGraphicList>(
 	ctx: impl ExtractAll + CloneVarArgs + Ctx,
 	/// Graphics to include within the artboard.
 	#[implementations(