Fix settings window style and Cmd+W close handling

Add NSToolbar to settings window so .unified toolbar style takes effect,
making the sidebar extend into the titlebar (matching standard macOS
Settings appearance). Add SettingsWindow subclass that responds to the
close: action from Ghostty's Close menu item, which otherwise goes
unhandled in non-terminal windows.

Author: nicosuave

macos/Ghostty.xcodeproj/project.pbxproj

@@ -115,6 +115,7 @@
 				Features/Settings/ConfigurationErrorsController.swift,
 				Features/Settings/ConfigurationErrorsView.swift,
 				Features/Settings/SettingsView.swift,
+				Features/Settings/SettingsWindow.swift,
 				Features/Splits/SplitTree.swift,
 				Features/Splits/SplitView.Divider.swift,
 				Features/Splits/SplitView.swift,

macos/Sources/App/macOS/AppDelegate.swift

@@ -1154,7 +1154,7 @@ class AppDelegate: NSObject,
 
     @IBAction func showSettings(_ sender: Any?) {
         if settingsWindowController == nil {
-            let window = NSWindow(
+            let window = SettingsWindow(
                 contentRect: NSRect(x: 0, y: 0, width: 720, height: 500),
                 styleMask: [.titled, .closable, .miniaturizable, .resizable],
                 backing: .buffered,
@@ -1164,7 +1164,12 @@ class AppDelegate: NSObject,
             window.center()
             window.isReleasedWhenClosed = false
             window.collectionBehavior = [.moveToActiveSpace]
+
+            let toolbar = NSToolbar(identifier: "SettingsToolbar")
+            toolbar.showsBaselineSeparator = false
+            window.toolbar = toolbar
             window.toolbarStyle = .unified
+
             window.minSize = NSSize(width: 680, height: 450)
             window.contentViewController = NSHostingController(rootView: SettingsView())
             settingsWindowController = NSWindowController(window: window)

macos/Sources/Features/Settings/SettingsWindow.swift

@@ -0,0 +1,15 @@
+import AppKit
+
+/// Custom NSWindow subclass for the Settings window.
+///
+/// Adds two things over a plain NSWindow:
+/// 1. Responds to the `close:` action sent by Ghostty's "Close" menu item
+///    (which maps to `close_surface`). Terminal views handle this natively,
+///    but non-terminal windows like Settings need to handle it explicitly.
+///    NSWindow.close() is ObjC selector `close` (no colon), so `close:`
+///    (with colon) is a distinct selector and doesn't conflict.
+class SettingsWindow: NSWindow {
+    @objc(close:) func closeFromMenu(_ sender: Any?) {
+        performClose(sender)
+    }
+}