[ark-render] refactor: use more general canvas return type

ArkKit/ark-render-kit/CanvasContext.swift

@@ -7,7 +7,7 @@ protocol CanvasContext<View> {
     var arkView: (any ArkView<View>)? { get }
     var memo: [EntityID: [RenderableComponentType: (any RenderableComponent, any Renderable)]] { get }
 
-    func getFlatCanvas() -> ArkFlatCanvas
+    func getFlatCanvas() -> any Canvas
     func render(_ canvas: any Canvas, using renderer: any RenderableBuilder<View>)
 }
 
@@ -62,7 +62,7 @@ class ArkCanvasContext<View>: CanvasContext {
     }
 
     /// Outputs a logical canvas with the relevant entities in the canvas and their renderable components only
-    func getFlatCanvas() -> ArkFlatCanvas {
+    func getFlatCanvas() -> any Canvas {
         var arkCanvas = ArkFlatCanvas()
         for renderableCompType in ArkCanvasSystem.renderableComponentTypes {
             let renderableEntities = ecs.getEntities(with: [renderableCompType])

ArkKit/ark-render-kit/canvas/Canvas.swift

@@ -22,4 +22,7 @@ protocol Canvas {
     typealias RenderableComponentType = ObjectIdentifier
     typealias CanvasElements = [EntityID: [RenderableComponentType: any RenderableComponent]]
     var canvasElements: CanvasElements { get }
+    mutating func addEntityRenderableToCanvas(entityId: EntityID,
+                                              componentType: RenderableComponentType,
+                                              renderableComponent: any RenderableComponent)
 }

ArkKitTests/data-structures-tests/OrderedDictionaryTests.swift

@@ -45,7 +45,7 @@ class OrderedDictionaryTests: XCTestCase {
             iteratedKeys.append(key)
         }
 
-        XCTAssertEqual(iteratedKeys, ["one", "two", "three"], 
+        XCTAssertEqual(iteratedKeys, ["one", "two", "three"],
                        "Keys should be iterated in the order they were inserted.")
     }