The standalone hint label sat in the form layout's field column with an
empty label cell, which misaligned it against the row above. Per review,
drop the label and carry its text in the spinbox tooltip instead.
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
