Stage 17 round 6 (cluster 1): profile, tap flash, variant naming, chat/nudge by turn

- Profile: drop the hint-balance line.
- Board: no mobile tap flash on a cell tap (-webkit-tap-highlight-color: transparent),
  matching the web click; the only intentional cell animation stays the last-word flash.
- Variant names keyed by the game's alphabet, not the UI language: english -> Scrabble
  always, russian_scrabble -> Скрэббл always (unlocalized, never collide), erudit localized.
- Chat/nudge are mutually exclusive by turn: the message field + Send show on your turn,
  the nudge replaces them on the opponent's turn; while the nudge cooldown is active the
  button is disabled with a grey 'awaiting reply' caption to its left.

ui/src/lib/i18n/en.ts

@@ -41,7 +41,7 @@ export const en = {
   'new.title': 'New game',
   'new.subtitle': 'Auto-match with another player',
   'new.english': 'Scrabble',
-  'new.russian': 'Scrabble',
+  'new.russian': 'Скрэббл',
   'new.erudit': 'Erudite',
   'new.find': 'Find a game',
   'new.searching': 'Looking for an opponent…',
@@ -96,6 +96,7 @@ export const en = {
   'chat.send': 'Send',
   'chat.nudge': 'Waiting for your move!',
   'chat.nudgeAction': 'Nudge',
+  'chat.awaitingReply': "Waiting for the opponent's reply",
   'chat.empty': 'No messages yet.',
   'chat.nudged': '{name} nudged you',