[Fonts] Restore DeckList Serif default and live-update all role readers (#7541)

* [Fonts] Restore DeckList Serif default and live-update all role readers

* [Fonts] Keep the DeckList fallback on the application font

DeckList is read by the deck editor headers, the filter tree and the deck
view too, not only by the two surfaces that hardcoded Serif. Resolving the
unset role to Serif in appFont() made every user without a fonts.toml see
Serif outside the deck list.

- appFont(DeckList) falls back to the application font again.
- ThemeManager::deckListFont() resolves the role and keeps the Serif
  fallback for the two historical sites: the deck view zone headers and
  the printed deck list.
- DeckView no longer repaints its viewport on fontsChanged; touching the
  scene items already schedules the repaint in every attached view.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/game_graphics/game_scene.cpp

@@ -1,6 +1,7 @@
 #include "game_scene.h"
 
 #include "../client/settings/cache_settings.h"
+#include "../interface/theme_manager.h"
 #include "animated_item.h"
 #include "board/abstract_card_item.h"
 #include "board/arrow_item.h"
@@ -64,6 +65,14 @@ GameScene::GameScene(PhasesToolbar *_phasesToolbar, QObject *parent)
     addItem(phasesToolbar);
     connect(&SettingsCache::instance().userInterface(), &InterfaceSettings::minPlayersForMultiColumnLayoutChanged, this,
             &GameScene::rearrange);
+    // CardText items (P/T boxes, counters, player names) read the role at
+    // paint time and cache their rendering, so touch every item to invalidate
+    // the caches and pick up the new family on font changes.
+    connect(themeManager, &ThemeManager::fontsChanged, this, [this] {
+        for (auto *item : items()) {
+            item->update();
+        }
+    });
 
     rearrange();
 }