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.

docs/FUNCTIONAL.md

@@ -204,13 +204,16 @@ client, and refuses a guest's friend request, friend code or invitation outright
 
 ### Playing a game
 Place tiles, pass, exchange, or resign. Pass and exchange share one control —
-choosing no tiles passes the turn, choosing tiles exchanges them. Tiles are laid
+choosing no tiles passes the turn, choosing tiles exchanges them. The tiles left in the
+bag are shown as a count on that control and at the foot of the move table. Tiles are laid
 without choosing a direction — the game infers the play's orientation, so a single
 tile that extends
 an existing word (down a column or across a row) is accepted. A play is validated
-against the game's dictionary at submit time and scored; an unlimited preview
-reports the word(s) a tentative move would form and its score, or that it is not
-legal, and the move is offered for submission only once it is confirmed legal. The preview is
+against the game's dictionary at submit time and scored; an unlimited preview shows
+**on the board itself** whether the tentative move is legal — the staged tiles turn a light
+green once they form a word, a shade darker on the board tiles the word runs through, or a
+calm pink when they form none — and an **orange badge** on the main word carries the move's
+score. The confirm control is offered only once the move is legal. The preview is
 computed **on-device** for an instant response once the game's dictionary has loaded — a
 brief warm-up shows on the first open otherwise — and falls back to the server whenever the
 local dictionary is unavailable. The dictionary check tool is
@@ -372,7 +375,9 @@ an email or Telegram and merging accounts are covered under "Accounts, linking &
 merge". Inside the Telegram Mini App, Telegram's own ⋮ menu also offers a **Settings**
 entry that opens this screen, and your display preferences (theme, board-label style and
 reduce-motion — not the interface language, which follows your account) sync across your
-Telegram devices.
+Telegram devices. On a touch device the settings also offer a **Zoom the board** toggle (on by
+default): with it off, dropping a tile no longer auto-magnifies the board toward it. It is a
+per-device preference and is hidden on desktop, where the board already fits and never auto-zooms.
 
 **Preferences (which variants you can be matched into).** A profile setting picks the game
 variants — Erudite, Russian Scrabble and English Scrabble, shown **Erudite-first** — you allow