Fix Enter in the merge dialog

mac/Sources/Byre/Dialogs.swift

@@ -61,6 +61,7 @@ final class Overlays {
     @ObservationIgnored weak var window: NSWindow?
     @ObservationIgnored private var monitor: Any?
     @ObservationIgnored private var mouseMonitor: Any?
+    @ObservationIgnored private weak var behindModal: NSResponder?
     @ObservationIgnored private var holders = 0
     @ObservationIgnored private var ctrl: @MainActor (String) -> Bool = { _ in false }
 
@@ -85,6 +86,11 @@ final class Overlays {
     func showModal(_ content: some View, _ buttons: @autoclosure @escaping @MainActor () -> [ModalButton], anchor: CGRect? = nil, inPane: Bool = false, canSubmit: @escaping @MainActor () -> Bool = { true }) async -> String {
         modal?.done("cancel")
         menu = nil
+        if modal == nil {
+            let responder = window?.firstResponder
+            behindModal = (responder as? NSTextView).flatMap { $0.isFieldEditor ? $0.delegate as? NSResponder : nil } ?? responder
+            window?.makeFirstResponder(nil)
+        }
         return await withCheckedContinuation { cont in
             modal = OverlayModal(content: AnyView(content), buttons: buttons, anchor: anchor, inPane: inPane, canSubmit: canSubmit) { value in
                 cont.resume(returning: value)
@@ -104,6 +110,10 @@ final class Overlays {
     func answerModal(_ value: String) {
         let m = modal
         modal = nil
+        if let behindModal, window?.firstResponder !== behindModal {
+            window?.makeFirstResponder(behindModal)
+        }
+        behindModal = nil
         m?.done(value)
     }