List fill, stroke, opacity, width and height as node property variables

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YaHo5D7kD3eWcagvzh3o3K

Author: claude

CHANGELOG.md

@@ -1,3 +1,10 @@
+## Unreleased
+
+- Every node with fills, strokes or opacity now lists `fill`, `stroke` and
+  `opacity` in its property variables, and every node lists `width` and
+  `height`, so conditions, bound variables and set value actions can change
+  them at runtime.
+
 ## 5.2.0
 
 ### New actions

lib/src/api/mixins.dart

@@ -1044,9 +1044,21 @@ mixin VariablePropertiesMixin {
 mixin PropertyVariableMixin on BaseNode {
   /// Properties of the node that can be used in actions or can be changed by
   /// an action.
+  ///
+  /// Style properties (fill, stroke, opacity, width, height) can be set by
+  /// conditions, bound to variables or formulas, or changed by a set value
+  /// action, on any node that has them.
   late final List<ValueModel> propertyVariables = [
     BoolValue(name: 'visible', value: visible),
     IntValue(name: 'rotationDegrees', value: rotationDegrees),
+    if (this case final GeometryMixin geometry) ...[
+      PaintValue(name: 'fill', value: geometry.fills.firstOrNull),
+      PaintValue(name: 'stroke', value: geometry.strokes.firstOrNull),
+    ],
+    if (this case final BlendMixin blend)
+      DoubleValue(name: 'opacity', value: blend.opacity),
+    DoubleValue(name: 'width', value: basicBoxLocal.width),
+    DoubleValue(name: 'height', value: basicBoxLocal.height),
   ];
 }