[macOS] feat: Add setting to hide icon from dock/cmd-tab

macos/Sources/App/macOS/AppDelegate.swift

@@ -523,6 +523,9 @@ class AppDelegate: NSObject,
         // this is called as part of application launch it can deadlock with an internal
         // AppKit mutex on the appearance.
         DispatchQueue.main.async { self.syncAppearance(config: config) }
+
+        // Decide whether to hide/unhide app from dock and cmd-tab
+        NSApp.setActivationPolicy(config.macosHidden ? .accessory : .regular)
 
         // If we have configuration errors, we need to show them.
         let c = ConfigurationErrorsController.sharedInstance

macos/Sources/Ghostty/Ghostty.Config.swift

@@ -300,6 +300,14 @@ extension Ghostty {
             return buffer.map { .init(ghostty: $0) }
         }
 
+        var macosHidden: Bool {
+            guard let config = self.config else { return false }
+            var v = false;
+            let key = "macos-hidden"
+            _ = ghostty_config_get(config, &v, key, UInt(key.count))
+            return v;
+        }
+
         var focusFollowsMouse : Bool {
             guard let config = self.config else { return false }
             var v = false;

src/config/Config.zig

@@ -1909,6 +1909,13 @@ keybind: Keybinds = .{},
 /// you may want to disable it.
 @"macos-secure-input-indication": bool = true,
 
+/// If true, the macOS icon in the dock and cmd-tab will be hidden. This is
+/// mainly intended for those primarily using the quick-terminal mode.
+///
+/// Note that setting this to true means that keyboard layout changes
+/// will no longer be automatic.
+@"macos-hidden": bool = false,
+
 /// Customize the macOS app icon.
 ///
 /// This only affects the icon that appears in the dock, application