fix(ui): name the default button on the quit prompt

Item 31. The user could not tell which button Enter would press on the
unsynced-changes dialog.

The code was already correct: setDefaultButton() is called, and Qt agrees,
isDefault() and hasFocus() are both true on "Sync and quit". The active
style, qt6ct-style, simply draws no visible default-button decoration. The
GIMP dialog offered for comparison is GTK drawing its own focus ring, a
different toolkit.

Naming the default in the text rather than restyling the button:
overriding the appearance means fighting the user's theme, which is worse
than one word. The safe option was already the default, so no behaviour
changed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index e546af5..b62d8d7 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -189,6 +189,15 @@ void MainWindow::closeEvent(QCloseEvent *event)
                 box.addButton(tr("Quit anyway"), QMessageBox::DestructiveRole);
             box.addButton(QMessageBox::Cancel);
             box.setDefaultButton(sync);
+
+            // The default is set correctly and Qt agrees (isDefault() and
+            // hasFocus() are both true on it), but qt6ct-style draws no
+            // visible default-button decoration, so Enter's target is
+            // invisible on this desktop. Naming it in the text costs nothing
+            // and does not fight the theme.
+            // ponytail: text, not a styled button. Restyling the button means
+            // overriding the user's theme, which is worse than a sentence.
+            sync->setText(tr("Sync and quit (default)"));
             box.exec();
 
             if (box.clickedButton() == sync) {