feat(ui): move in-game status to the board — highlight, score badge, full-width rack

Remove the under-board status strip and relocate its signals:
- bag count -> a badge on the exchange/pass control + the foot of the move table
- whose-turn / win-lose -> a thin strip above the score plaques
- the tentative-move caption -> the board itself: staged tiles tint green (legal) or
  pink (illegal), the board tiles a formed word runs through go a shade darker, and an
  orange score badge sits on the main word (digit sized like a tile value, clamped on-board)

The word geometry (covered cells + badge anchor) is a new pure client-side helper
(ui/src/lib/formed.ts), independent of the move evaluator, so it works on the local or
network preview path alike; the badge's number still comes from the preview score.

Rack: a seven-column grid filling the tray width in both layouts — square, full-width
tiles — with the confirm control in the fixed 7th slot.

Settings: a touch-only "Zoom the board" toggle (default on, device-local) gates the
tile-placement auto-zoom; taking a hint while zoomed in now zooms out so the highlighted
hint word is never left off-screen.

Docs (FUNCTIONAL +_ru, UI_DESIGN, ARCHITECTURE) and e2e/unit tests updated.

ui/src/lib/i18n/ru.ts

@@ -104,8 +104,6 @@ export const ru: Record<MessageKey, string> = {
   'game.checkWord': 'Проверить слово',
   'game.dictionary': 'Словарь',
   'game.dropGame': 'Покинуть игру',
-  'game.previewWords': '{words}: {n}',
-  'game.previewIllegal': 'Недопустимый ход',
   'game.oneWordRule': 'Одно слово за ход',
   'game.chooseBlank': 'Выберите букву для бланка',
   'game.exchangeTitle': 'Обмен или пас',
@@ -215,6 +213,7 @@ export const ru: Record<MessageKey, string> = {
   'settings.labelsClassic': 'Классика',
   'settings.labelsNone': 'Без текста',
   'settings.reduceMotion': 'Меньше анимаций',
+  'settings.zoomBoard': 'Приближать доску',
   'settings.offlineMode': 'Режим игры',
   'settings.online': 'Онлайн',
   'settings.offline': 'Оффлайн',