Add a mechanism to customize app icons and colors

compound-ios/Sources/Compound/Icons/CompoundIcon.swift

@@ -51,7 +51,9 @@ public struct CompoundIcon: View {
     /// - Parameters:
     ///   - icon: The icon to show.
     public init(_ icon: KeyPath<CompoundIcons, Image>) {
-        image = .compound[keyPath: icon]
+        // Letro: Add a mechanism to override icons
+        image = Self.resolve(icon)
+        
         size = .medium
         font = .compound.bodyLG
     }
@@ -63,7 +65,9 @@ public struct CompoundIcon: View {
     ///   - size: The size of the icon.
     ///   - font: The font that should be used for scaling with Dynamic Type.
     public init(_ icon: KeyPath<CompoundIcons, Image>, size: Size, relativeTo font: Font) {
-        image = .compound[keyPath: icon]
+        // Letro: Add a mechanism to override icons
+        image = Self.resolve(icon)
+        
         self.size = size
         self.font = font
     }
@@ -102,6 +106,15 @@ public struct CompoundIcon: View {
             .resizable()
             .modifier(CompoundIconFrame(fontSize: size.value, textStyle: fontSize.style))
     }
+
+    // Letro: Add a mechanism to override icons
+    private static var overrides = [AnyKeyPath: Image]()
+    public static func override(_ keyPath: KeyPath<CompoundIcons, Image>, with image: Image?) {
+        overrides[keyPath] = image
+    }
+    private static func resolve(_ keyPath: KeyPath<CompoundIcons, Image>) -> Image {
+        overrides[keyPath] ?? .compound[keyPath: keyPath]
+    }
 }
 
 /// A simple modifier that applies a square frame of a given size that will be