fix(engine): send confirmed:true from game-over screen New Game handlers

The 'No Moves Available' dialog's New Game button and keyboard shortcut
were firing NewGameRequestEvent::default() (confirmed: false). When the
player has made moves, handle_new_game sees needs_confirm = true, then
hits the scrims.is_empty() guard — which is false because the GameOver-
Screen itself is a ModalScrim — and silently returns without starting a
new game or showing the confirm dialog.

Fix: set confirmed: true in both handle_game_over_input (N/Escape key)
and handle_game_over_button_input (click). The game is already stuck so
the abandon-confirmation guard does not apply, as the doc comment on the
button handler has always said.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_engine/src/game_plugin.rs

@@ -1190,7 +1190,8 @@ fn handle_game_over_input(
     };
 
     if keys.just_pressed(KeyCode::KeyN) || keys.just_pressed(KeyCode::Escape) {
-        new_game.write(NewGameRequestEvent::default());
+        // confirmed: true — the game is already stuck; no abandon-confirmation needed.
+        new_game.write(NewGameRequestEvent { confirmed: true, ..default() });
     } else if keys.just_pressed(KeyCode::KeyU) {
         for entity in &screens {
             commands.entity(entity).despawn();
@@ -1217,7 +1218,8 @@ fn handle_game_over_button_input(
         return;
     }
     if new_game_buttons.iter().any(|i| *i == Interaction::Pressed) {
-        new_game.write(NewGameRequestEvent::default());
+        // confirmed: true — the game is already stuck; no abandon-confirmation needed.
+        new_game.write(NewGameRequestEvent { confirmed: true, ..default() });
     } else if undo_buttons.iter().any(|i| *i == Interaction::Pressed) {
         for entity in &screens {
             commands.entity(entity).despawn();