macos: update accessory in the titlebar should not move the window

This is annoyingly easy to trigger, just disable this.

macos/Ghostty.xcodeproj/project.pbxproj

@@ -167,6 +167,7 @@
 				Helpers/KeyboardLayout.swift,
 				Helpers/LastWindowPosition.swift,
 				Helpers/MetalView.swift,
+				Helpers/NonDraggableHostingView.swift,
 				Helpers/PermissionRequest.swift,
 				Helpers/Private/CGS.swift,
 				Helpers/Private/Dock.swift,

macos/Sources/Features/Terminal/Window Styles/TerminalWindow.swift

@@ -108,7 +108,7 @@ class TerminalWindow: NSWindow {
             // Create update notification accessory
             if supportsUpdateAccessory {
                 updateAccessory.layoutAttribute = .right
-                updateAccessory.view = NSHostingView(rootView: UpdateAccessoryView(
+                updateAccessory.view = NonDraggableHostingView(rootView: UpdateAccessoryView(
                     viewModel: viewModel,
                     model: appDelegate.updateViewModel
                 ))

macos/Sources/Helpers/NonDraggableHostingView.swift

@@ -0,0 +1,13 @@
+import SwiftUI
+
+/// An NSHostingView subclass that prevents window dragging when clicking on the view.
+///
+/// By default, NSHostingViews in the titlebar allow the window to be dragged when
+/// clicked. This subclass overrides `mouseDownCanMoveWindow` to return false,
+/// preventing the window from being dragged when the user clicks on this view.
+///
+/// This is useful for titlebar accessories that contain interactive elements
+/// (buttons, links, etc.) where you don't want accidental window dragging.
+class NonDraggableHostingView<Content: View>: NSHostingView<Content> {
+    override var mouseDownCanMoveWindow: Bool { false }
+}