Add bell feature flags for audio, attention, and title actions on macOS

Signed-off-by: Aaron Ruan <i@ar212.com>

macos/Sources/App/macOS/AppDelegate.swift

@@ -530,11 +530,13 @@ class AppDelegate: NSObject,
     }
 
     @objc private func ghosttyBellDidRing(_ notification: Notification) {
-        // Bounce the dock icon if we're not focused.
-        NSApp.requestUserAttention(.informationalRequest)
+        if (ghostty.config.bellFeatures.contains(.attention)) {
+            // Bounce the dock icon if we're not focused.
+            NSApp.requestUserAttention(.informationalRequest)
 
-        // Handle setting the dock badge based on permissions
-        ghosttyUpdateBadgeForBell()
+            // Handle setting the dock badge based on permissions
+            ghosttyUpdateBadgeForBell()
+        }
     }
 
     private func ghosttyUpdateBadgeForBell() {

macos/Sources/Ghostty/Ghostty.Config.swift

@@ -566,6 +566,9 @@ extension Ghostty.Config {
         let rawValue: CUnsignedInt
 
         static let system = BellFeatures(rawValue: 1 << 0)
+        static let audio = BellFeatures(rawValue: 1 << 1)
+        static let attention = BellFeatures(rawValue: 1 << 2)
+        static let title = BellFeatures(rawValue: 1 << 3)
     }
 
     enum MacHidden : String {

macos/Sources/Ghostty/SurfaceView.swift

@@ -59,7 +59,7 @@ extension Ghostty {
 
         var title: String {
             var result = surfaceView.title
-            if (surfaceView.bell) {
+            if (surfaceView.bell && ghostty.config.bellFeatures.contains(.title)) {
                 result = "🔔 \(result)"
             }