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
