Add styled DMG with arrow pointing to Applications (#5445)

* Add styled DMG with arrow pointing to Applications

- Add create-dmg as a bazel dependency for creating styled DMG installers
- Add background image with arrow pointing from app to Applications
- Update mac_build_handler to use create-dmg for styled DMG creation
- Update CI workflow to use the new DMG creation process

The DMG now shows a visual arrow guiding users to drag the app
to the Applications folder.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add --skip-jenkins flag for headless CI environment

The AppleScript that positions icons times out in CI environments
without a GUI session. Using --skip-jenkins skips the Finder styling
while still including the background image and Applications link.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Switch from create-dmg to dmgbuild for CI compatibility

dmgbuild generates .DS_Store files programmatically without needing
AppleScript or Finder access, making it work in headless CI environments.

- Remove create-dmg bazel dependency (relied on AppleScript)
- Use dmgbuild Python tool instead (pip install dmgbuild)
- Generates proper icon positions and background without GUI

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix DMG styling: lighter background, adjust icon positions

- Use light gray background so file/folder names are readable
- Move arrow up to align with icon centers
- Move Applications link further right (500 -> 520) to clear the arrow

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix arrow: move left, connect head to shaft properly

- Arrow now starts at x=200 (closer to app icon)
- Arrow ends at x=460 (further from Applications at x=520)
- Head and shaft now overlap for proper connection

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/mac_build.yml

@@ -263,6 +263,12 @@ jobs:
           echo "$SPARKLE_EDDSA_PRIVATE_KEY" > "$SPARKLE_PRIVATE_KEY_PATH"
           chmod 600 "$SPARKLE_PRIVATE_KEY_PATH"
 
+          # Install dmgbuild (creates .DS_Store programmatically, no AppleScript needed)
+          pip3 install dmgbuild
+
+          # Background image for styled DMG
+          BACKGROUND_PATH="$(pwd)/ci/mac/dmg/background.png"
+
           # Use commit count for automatic incrementing versions (e.g., 1.0.9548)
           BUILD_NUMBER=$(git rev-list --count HEAD)
           VERSION="1.0.${BUILD_NUMBER}"
@@ -271,6 +277,7 @@ jobs:
             "/tmp/eagle0/eagle0MAC/eagle0.app" \
             "$VERSION" \
             "$BUILD_NUMBER" \
+            "$BACKGROUND_PATH" \
             "$SPARKLE_PRIVATE_KEY_PATH"
 
           rm "$SPARKLE_PRIVATE_KEY_PATH"

src/main/go/net/eagle0/build/mac_build_handler/mac_build_handler.go

@@ -51,47 +51,72 @@ type Enclosure struct {
 	EdSig  string `xml:"sparkle:edSignature,attr"`
 }
 
-func createDMG(appPath string, dmgPath string, volumeName string) error {
-	// Create a temporary directory for the DMG contents
-	tmpDir, err := os.MkdirTemp("", "dmg-contents-")
-	if err != nil {
-		return fmt.Errorf("failed to create temp dir: %w", err)
-	}
-	defer os.RemoveAll(tmpDir)
-
-	// Copy the app to the temp directory
-	appName := filepath.Base(appPath)
-	destApp := filepath.Join(tmpDir, appName)
-	log.Printf("Copying %s to %s", appPath, destApp)
-
-	// Use ditto to preserve all metadata, permissions, and symlinks
-	cmd := exec.Command("ditto", appPath, destApp)
-	if output, err := cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("failed to copy app: %s: %w", string(output), err)
-	}
-
-	// Create an alias to /Applications
-	applicationsAlias := filepath.Join(tmpDir, "Applications")
-	cmd = exec.Command("ln", "-s", "/Applications", applicationsAlias)
-	if output, err := cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("failed to create Applications symlink: %s: %w", string(output), err)
-	}
-
+func createDMG(appPath string, dmgPath string, volumeName string, backgroundPath string) error {
 	// Remove any existing DMG
 	os.Remove(dmgPath)
 
-	// Create the DMG using hdiutil
-	// -volname: Name shown when mounted
-	// -srcfolder: Source directory
-	// -ov: Overwrite existing
-	// -format UDZO: Compressed DMG (read-only)
-	log.Printf("Creating DMG: %s", dmgPath)
-	cmd = exec.Command("hdiutil", "create",
-		"-volname", volumeName,
-		"-srcfolder", tmpDir,
-		"-ov",
-		"-format", "UDZO",
-		dmgPath)
+	log.Printf("Creating styled DMG: %s", dmgPath)
+
+	// Create a temporary dmgbuild settings file
+	settingsFile, err := os.CreateTemp("", "dmgbuild-settings-*.py")
+	if err != nil {
+		return fmt.Errorf("failed to create settings file: %w", err)
+	}
+	defer os.Remove(settingsFile.Name())
+
+	appName := filepath.Base(appPath)
+
+	// dmgbuild settings - generates .DS_Store programmatically without AppleScript
+	settings := fmt.Sprintf(`
+# dmgbuild settings for Eagle0
+import os
+
+# Volume name
+volume_name = %q
+
+# Output format
+format = 'UDZO'
+
+# Volume size (None = auto)
+size = None
+
+# Files to include
+files = [
+    (%q, %q),
+]
+
+# Symlinks
+symlinks = {
+    'Applications': '/Applications',
+}
+
+# Background image
+background = %q
+
+# Window settings
+icon_size = 128
+icon_locations = {
+    %q: (140, 180),
+    'Applications': (520, 180),
+}
+
+# Window position and size
+window_rect = ((100, 100), (660, 400))
+
+# Hide standard folders
+hide_extensions = ['app']
+`, volumeName, appPath, appName, backgroundPath, appName)
+
+	if _, err := settingsFile.WriteString(settings); err != nil {
+		return fmt.Errorf("failed to write settings: %w", err)
+	}
+	settingsFile.Close()
+
+	// Run dmgbuild
+	cmd := exec.Command("dmgbuild", "-s", settingsFile.Name(), volumeName, dmgPath)
+	cmd.Env = append(os.Environ(), "PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:"+os.Getenv("HOME")+"/.local/bin")
+
+	log.Printf("Running: dmgbuild -s %s %s %s", settingsFile.Name(), volumeName, dmgPath)
 	if output, err := cmd.CombinedOutput(); err != nil {
 		return fmt.Errorf("failed to create DMG: %s: %w", string(output), err)
 	}
@@ -198,34 +223,39 @@ func uploadAppcast(bb aws.BucketBasics, appcast *Appcast) error {
 }
 
 func main() {
-	if len(os.Args) < 4 {
-		fmt.Println("Usage: mac_build_handler <app_path> <version> <build_number> [sparkle_private_key_path]")
+	if len(os.Args) < 5 {
+		fmt.Println("Usage: mac_build_handler <app_path> <version> <build_number> <background_path> [sparkle_private_key_path]")
 		os.Exit(1)
 	}
 
 	appPath := os.Args[1]
 	version := os.Args[2]
 	buildNumber := os.Args[3]
+	backgroundPath := os.Args[4]
 	privateKeyPath := ""
-	if len(os.Args) >= 5 {
-		privateKeyPath = os.Args[4]
+	if len(os.Args) >= 6 {
+		privateKeyPath = os.Args[5]
 	}
 
 	if _, err := os.Stat(appPath); os.IsNotExist(err) {
 		log.Fatalf("App not found: %s", appPath)
 	}
 
+	if _, err := os.Stat(backgroundPath); os.IsNotExist(err) {
+		log.Fatalf("Background image not found: %s", backgroundPath)
+	}
+
 	bb, err := aws.NewBucketBasics()
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	// Create DMG of the app
+	// Create DMG of the app using dmgbuild (generates .DS_Store programmatically)
 	dmgFileName := fmt.Sprintf("eagle0-%s.dmg", version)
 	dmgPath := filepath.Join("/tmp", dmgFileName)
 
 	log.Printf("Creating DMG: %s", dmgPath)
-	if err := createDMG(appPath, dmgPath, "Eagle0"); err != nil {
+	if err := createDMG(appPath, dmgPath, "Eagle0", backgroundPath); err != nil {
 		log.Fatalf("Failed to create DMG: %v", err)
 	}