feat(ui): lobby invitation card redesign + new-game tweaks

- Lobby friend-invitation card: icon-only checkmark/cross actions stacked in a
  min-width right column; the middle column (From <name> + flag + variant rules,
  like New Game) grows and wraps. The cross now opens a decline-confirmation modal
  (mirroring the in-game resign confirm) instead of declining on first tap.
- New Game with a friend: a lone offered variant is pre-selected and its picker
  disabled (nothing else to choose); relabel 'Тип игры' -> 'Вариант' and
  'Подсказок на игрока' -> 'Подсказки'.
- Quick game: pin the Start button to the bottom of the screen, mirroring the
  friend-game Send-invitation button.

ui/src/lib/i18n/en.ts

@@ -257,6 +257,7 @@ export const en = {
   'invitations.with': 'With {names}',
   'invitations.accept': 'Accept',
   'invitations.decline': 'Decline',
+  'invitations.declineConfirm': 'Decline invitation?',
   'invitations.cancel': 'Cancel',
   'invitations.waiting': 'Waiting for replies',
 
@@ -264,10 +265,10 @@ export const en = {
   'new.withFriends': 'Play with friends',
   'new.pickFriends': 'Choose who to invite',
   'new.searchFriends': 'Search friends',
-  'new.gameType': 'Game type',
+  'new.gameType': 'Variant',
   'new.invite': 'Send invitation',
   'new.moveTime': 'Move time',
-  'new.hintsPerPlayer': 'Hints per player',
+  'new.hintsPerPlayer': 'Hints',
   'new.multipleWordsPerTurn': 'Multiple words per turn',
   'new.start': 'Start game',
   'new.invited': 'Invitation sent.',