feat(stats): best-move word, moves & hint-share, and a hint-count fix (#81)

The statistics screen gains real depth, plus a hint-count bug fix found along the way.

- Best move per variant: the screen shows the actual best-move word (drawn as game
  tiles; a wildcard shows its letter but no value), broken down by game variant, empty
  variants omitted. New account_best_move table, written at game finish.
- Moves & hint share: two new lifetime tiles — the player's play count and the share of
  plays that used a hint — from summed account_stats counters (moves, hints_used).
  Honest-AI games are excluded, like the rest of the stats.
- Hint-count fix: the in-game hint badge no longer goes stale across games. The global
  wallet now rides the wire apart from the per-game allowance (wallet_balance on
  StateView/HintResult/StatsView), so the client reads the live wallet rather than a
  per-game snapshot; game_players.hints_used now counts every hint (allowance + wallet),
  its true per-game total.
- Account merge: sums the new moves/hints_used counters and merges the per-variant best
  moves (higher score kept), which it previously dropped.
- Admin: the user card shows Moves and Hints used.
- UI polish: tab/label wording, game-over text, and e2e selectors hardened against label
  changes.

All wire additions are trailing (backward-compatible). Docs (ARCHITECTURE, FUNCTIONAL +ru,
UISN_DESIGN) updated in step.

ui/src/lib/i18n/en.ts

@@ -34,7 +34,7 @@ export const en = {
   'lobby.noActive': 'No active games yet.',
   'lobby.noFinished': 'No finished games yet.',
   'lobby.limitReached': "You've reached the simultaneous games limit.",
-  'lobby.new': 'New',
+  'lobby.new': 'Play',
   'lobby.stats': 'Stats',
   'lobby.profile': 'Profile',
   'lobby.settings': 'Settings',
@@ -83,7 +83,6 @@ export const en = {
   'game.passNoExchange': 'Pass without exchanging',
   'game.confirmResign': 'Resign this game?',
   'game.hintShown': 'Best move: {word} for {n}',
-  'game.over': 'Game over',
   'game.won': 'You won',
   'game.lost': 'You lost',
   'game.tied': 'Draw',
@@ -118,7 +117,7 @@ export const en = {
   'chat.nudge': 'Waiting for your move 🤭',
   'chat.nudgeBy': '{name}: Waiting for your move 🤭',
   'chat.nudgeAction': 'Nudge',
-  'chat.awaitingReply': "Waiting for the opponent's reply",
+  'chat.awaitingReply': "Let's be patient",
   'chat.empty': 'No messages yet.',
   'chat.nudged': '{name} nudged you',
   'chat.sentThisTurn': 'You can write again next turn.',
@@ -275,6 +274,8 @@ export const en = {
   'stats.losses': 'Losses',
   'stats.draws': 'Draws',
   'stats.played': 'Games',
+  'stats.moves': 'Moves',
+  'stats.hintShare': 'Hint share',
   'stats.winRate': 'Win rate',
   'stats.maxGame': 'Best game',
   'stats.maxWord': 'Best move',