Replace ImageMagick with a custom tool written in swift.

Tools/Sources/AppIconBanner.swift

@@ -0,0 +1,67 @@
+import ArgumentParser
+import SwiftUI
+
+struct AppIconBanner: AsyncParsableCommand {
+    static var configuration = CommandConfiguration(
+        abstract: "A Swift command-line tool to add a banner to an app icons."
+    )
+    
+    @Argument(help: "Path to the input image.")
+    var path: String
+        
+    @Option(help: "Text for the banner.")
+    var bannerText: String
+        
+    @MainActor
+    func run() async throws {
+        let currentDirectoryURL = URL(filePath: FileManager.default.currentDirectoryPath)
+        let pathURL = currentDirectoryURL.appending(path: path)
+        
+        guard let image = NSImage(contentsOf: pathURL) else {
+            throw ValidationError("Could not load the image at \(pathURL).")
+        }
+        
+        let renderer = ImageRenderer(content: BannerImage(image: image,
+                                                          text: bannerText))
+        
+        do {
+            guard let cgImage = renderer.cgImage else {
+                throw ValidationError("Couldn't generate CG image.")
+            }
+            
+            let bitmap = NSBitmapImageRep(cgImage: cgImage)
+            
+            guard let pngData = bitmap.representation(using: .png, properties: [:]) else {
+                throw ValidationError("Couldn't create png data from image.")
+            }
+            
+            try pngData.write(to: pathURL)
+            print("Successfully saved the image with a banner to \(pathURL).")
+        } catch {
+            throw ValidationError("Failed to save the image: \(error).")
+        }
+    }
+}
+
+struct BannerImage: View {
+    let image: NSImage
+    let text: String
+    
+    var body: some View {
+        ZStack(alignment: .bottom) {
+            Image(nsImage: image)
+                .resizable()
+                .aspectRatio(contentMode: .fit)
+            
+            Text(text)
+                .frame(maxWidth: .infinity)
+                .padding()
+                .background(Color.black.opacity(0.5))
+                .foregroundColor(.white)
+                .font(.system(size: 140))
+                .lineLimit(1)
+                .allowsTightening(true)
+        }
+        .frame(width: image.size.width, height: image.size.height)
+    }
+}

Tools/Sources/Tools.swift

@@ -2,7 +2,7 @@ import ArgumentParser
 import Foundation
 
 @main
-struct Tools: ParsableCommand {
+struct Tools: AsyncParsableCommand {
     static var configuration = CommandConfiguration(abstract: "A collection of command line tools for ElementX",
                                                     subcommands: [BuildSDK.self,
                                                                   SetupProject.self,
@@ -10,5 +10,6 @@ struct Tools: ParsableCommand {
                                                                   DownloadStrings.self,
                                                                   Locheck.self,
                                                                   GenerateSDKMocks.self,
-                                                                  GenerateSAS.self])
+                                                                  GenerateSAS.self,
+                                                                  AppIconBanner.self])
 }