Stage 7 (wip): docs bake + stage renumber (insert UI Stage 8, shift +1)

- PLAN.md: new Stage 8 (UI social/account/history); Telegram->9, Admin->10, Linking->11, Polish->12; tracker + Stage 7 refinements; split the Stage 6 'wired in Stage 7' note between 7 and 8
- ARCHITECTURE: promote ui to current (slice scope, board-replay, codegen, theming, mock)
- FUNCTIONAL(+ru): client-app section with the Stage 7/8 split
- README + ui/README + CLAUDE.md: UI build/run/test, codegen, pnpm notes
- bumped Stage 8-11 refs (+1) across docs and code comments

docs/FUNCTIONAL.md

@@ -9,6 +9,16 @@ the detail is authored.
 
 ## Domains
 
+### Client app *(Stage 7 / 8)*
+The web/app client (Svelte + Vite) realizes these stories. The **playable slice**
+(Stage 7) covers signing in (guest or email), the "my games" lobby, starting an
+auto-match, playing the board (place tiles by drag or tap, pass, exchange, resign),
+the top-1 hint, the unlimited word-check with complaint, per-game chat and nudge,
+real-time in-app updates, switching interface language (en/ru) and theme, and a
+read-only profile. Managing friends and blocks, creating friend games (invitations),
+editing the profile, the statistics screen and the history/GCG viewer arrive in
+Stage 8.
+
 ### Identity & sessions *(Stage 1 / 6)*
 A player arrives from a platform (Telegram first), via email login, or as an
 ephemeral guest. The gateway validates the credential once and mints a thin
@@ -17,7 +27,7 @@ session-only with restricted features (auto-match only; no friends, stats or
 history). While the app is open the client keeps a live stream and receives
 in-app updates in real time — the opponent's move, your turn, chat, nudges and a
 found match; out-of-app push (your turn, nudge) is delivered by the platform
-later (Stage 8).
+later (Stage 9).
 
 ### Accounts, linking & merge *(Stage 1 / 10)*
 First platform contact auto-provisions a durable account. From the profile a
@@ -76,7 +86,7 @@ Edit language (en/ru), display name, timezone, the daily away window and the blo
 toggles, and bind an email by confirm-code: the backend emails a short code that,
 once entered, attaches the email to the account (an email already confirmed by
 another account cannot be taken — that is a merge, a later stage). Linked platform
-accounts and merge arrive in Stage 10.
+accounts and merge arrive in Stage 11.
 
 ### History & statistics *(Stage 3)*
 Finished games are archived in a dictionary-independent form and exportable to
@@ -84,6 +94,6 @@ GCG. Statistics (durable accounts only): wins, losses, draws, max points in a
 game, and max points for a single move (the best play, which already includes
 every word it formed plus the all-tiles bonus).
 
-### Administration *(Stage 9)*
+### Administration *(Stage 10)*
 Admin (Basic Auth at the gateway) reviews word complaints, manages dictionary
 versions, and inspects users/games.