[Client] Add tournament UI for creating and following lobby tournaments

Wires the tournament protocol into the client:
- DlgCreateGame gains a tournament checkbox with a games-per-match
  settings sub-dialog; both values are sent with Command_CreateGame and
  mirrored in the join-info variant of the dialog
- TournamentWidget renders live standings (with deck-submission state)
  and pairings for the local player's perspective, and asks to open the
  current match game via openMatchGameRequested()
- TournamentTabGameExtension attaches an overview page to TabGame's
  stacked views, mirrors phase and submission progress onto a deck-view
  status strip, and provides round-trip navigation between game view and
  standings; hosts get an in-game settings dialog during deck building
- Open-match falls back to joining as spectator through TabSupervisor;
  sub-games now return to their parent tab on close, falling back to
  the normal leave-game flow when the parent is gone

cockatrice/src/interface/widgets/tabs/tab_game.cpp

@@ -33,6 +33,7 @@
 #include "card_database_display_model.h"
 #include "card_database_model.h"
 #include "tab_supervisor.h"
+#include "tournament_tab_game_extension.h"
 
 #include <QAction>
 #include <QApplication>
@@ -134,6 +135,10 @@ TabGame::TabGame(TabSupervisor *_tabSupervisor,
     createMenuItems();
     createViewMenuItems();
 
+    if (game->getGameMetaInfo()->isTournament()) {
+        tournamentExtension = new TournamentTabGameExtension(this);
+    }
+
     connectToGameState();
     connectToPlayerManager();
     connectToGameEventHandler();
@@ -150,6 +155,10 @@ TabGame::TabGame(TabSupervisor *_tabSupervisor,
         gameTypes.append(game->getGameMetaInfo()->findRoomGameType(i));
     }
 
+    if (tournamentExtension) {
+        tournamentExtension->initializeTournamentMode();
+    }
+
     QTimer::singleShot(0, this, &TabGame::loadLayout);
 }
 
@@ -400,6 +409,10 @@ void TabGame::retranslateUi()
     }
 
     scene->retranslateUi();
+
+    if (tournamentExtension) {
+        tournamentExtension->retranslateUi();
+    }
 }
 
 void TabGame::refreshShortcuts()
@@ -928,8 +941,22 @@ void TabGame::stopGame()
     }
 }
 
+bool TabGame::switchToGameTab(int gameId)
+{
+    return tabSupervisor->switchToGameTabIfAlreadyExists(gameId);
+}
+
 void TabGame::closeGame()
 {
+    int parentId = game->getGameMetaInfo()->parentGameId();
+    if (parentId >= 0) {
+        if (switchToGameTab(parentId)) {
+            close();
+        }
+        // If the parent tab is gone, fall through to the normal leave-game
+        // flow instead of stranding the user on a dead sub-game tab.
+    }
+
     gameMenu->clear();
     gameMenu->addAction(aLeaveGame);
 }