macOS: distinguish between Debug and Release(Stable/Tip) (#9149)

### Background

Been running Ghostty locally for a while now, and I use the Finder
service a lot. It often confuses me which one is the official one, until
I actually open it.

### Changes

- Use blueprint to distinguish from release app, if no custom icon
specified
- Change BundleDisplayName to Ghostty[Debug]
- Enable Info.plist preprocessing for reading
`$(INFOPLIST_KEY_CFBundleDisplayName)` for providing different services
with different configurations
> (Preprocessing was once reverted
before](https://github.com/ghostty-org/ghostty/commit/6508fec), so I'm
not sure whether this follows the 'rules' here, but for now, there are
no links in the plist file, so I think it’s
[safe](https://developer.apple.com/library/archive/technotes/tn2175/_index.html#:~:text=can%20pass%20the-,%2Dtraditional,-flag%20to%20the)
to enable it

macos/Ghostty-Info.plist

@@ -61,7 +61,7 @@
 			<key>NSMenuItem</key>
 			<dict>
 				<key>default</key>
-				<string>New Ghostty Tab Here</string>
+				<string>New $(INFOPLIST_KEY_CFBundleDisplayName) Tab Here</string>
 			</dict>
 			<key>NSMessage</key>
 			<string>openTab</string>
@@ -80,7 +80,7 @@
 			<key>NSMenuItem</key>
 			<dict>
 				<key>default</key>
-				<string>New Ghostty Window Here</string>
+				<string>New $(INFOPLIST_KEY_CFBundleDisplayName) Window Here</string>
 			</dict>
 			<key>NSMessage</key>
 			<string>openWindow</string>

macos/Ghostty.xcodeproj/project.pbxproj

@@ -553,6 +553,7 @@
 				INFOPLIST_KEY_NSRemindersUsageDescription = "A program running within Ghostty would like to access your reminders.";
 				INFOPLIST_KEY_NSSpeechRecognitionUsageDescription = "A program running within Ghostty would like to use speech recognition.";
 				INFOPLIST_KEY_NSSystemAdministrationUsageDescription = "A program running within Ghostty requires elevated privileges.";
+				INFOPLIST_PREPROCESS = YES;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/../Frameworks",
@@ -775,7 +776,7 @@
 				EXECUTABLE_NAME = ghostty;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = "Ghostty-Info.plist";
-				INFOPLIST_KEY_CFBundleDisplayName = Ghostty;
+				INFOPLIST_KEY_CFBundleDisplayName = "Ghostty[DEBUG]";
 				INFOPLIST_KEY_LSApplicationCategoryType = "public.app-category.developer-tools";
 				INFOPLIST_KEY_NSAppleEventsUsageDescription = "A program running within Ghostty would like to use AppleScript.";
 				INFOPLIST_KEY_NSBluetoothAlwaysUsageDescription = "A program running within Ghostty would like to use Bluetooth.";
@@ -793,6 +794,7 @@
 				INFOPLIST_KEY_NSRemindersUsageDescription = "A program running within Ghostty would like to access your reminders.";
 				INFOPLIST_KEY_NSSpeechRecognitionUsageDescription = "A program running within Ghostty would like to use speech recognition.";
 				INFOPLIST_KEY_NSSystemAdministrationUsageDescription = "A program running within Ghostty requires elevated privileges.";
+				INFOPLIST_PREPROCESS = YES;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/../Frameworks",
@@ -847,6 +849,7 @@
 				INFOPLIST_KEY_NSRemindersUsageDescription = "A program running within Ghostty would like to access your reminders.";
 				INFOPLIST_KEY_NSSpeechRecognitionUsageDescription = "A program running within Ghostty would like to use speech recognition.";
 				INFOPLIST_KEY_NSSystemAdministrationUsageDescription = "A program running within Ghostty requires elevated privileges.";
+				INFOPLIST_PREPROCESS = YES;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/../Frameworks",
@@ -865,7 +868,7 @@
 		A5D449A82B53AE7B000F5B83 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				ASSETCATALOG_COMPILER_APPICON_NAME = Ghostty;
+				ASSETCATALOG_COMPILER_APPICON_NAME = "Ghostty-Debug";
 				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;

macos/Sources/App/macOS/AppDelegate.swift

@@ -121,7 +121,12 @@ class AppDelegate: NSObject,
     /// The custom app icon image that is currently in use.
     @Published private(set) var appIcon: NSImage? = nil {
         didSet {
+#if DEBUG
+            // if no custom icon specified, we use blueprint to distinguish from release app
+            NSApplication.shared.applicationIconImage = appIcon ?? NSImage(named: "BlueprintImage")
+#else
             NSApplication.shared.applicationIconImage = appIcon
+#endif
             let appPath = Bundle.main.bundlePath
             NSWorkspace.shared.setIcon(appIcon, forFile: appPath, options: [])
             NSWorkspace.shared.noteFileSystemChanged(appPath)