Stage 8: UI social/account/history surfaces

Wire the deferred Stage 7 surfaces end-to-end (UI -> gateway transcode ->
backend REST -> existing domain services): friends (incl. one-time friend
codes), per-user blocks, friend-game invitations, profile editing + email
binding, the statistics screen, and the in-game history + GCG export.

Friends gain two add paths (interview decision, a deliberate plan change):
one-time 6-digit codes (friend_codes table, 12h TTL, single-use, rate-limited
redeem); and play-gated requests (shared game required) where an explicit
decline is permanent, an ignored request lapses after 30 days, and a code
bypasses a decline. Migration 00006 widens friendships_status_chk and adds
friend_codes.

Lobby notification badge is poll + push: a new generic `notify` event drives
it live; the client polls on open/focus. Language stays a single Settings
control that writes through to the durable account's preferred_language. GCG
export is finished-only (game.ErrGameActive) and shares/downloads the .gcg file.

Tests: backend unit + inttest (friend gate/decline/code, ListInvitations,
GetStats, GCG gate), gateway transcode round-trips + notify constructor, UI
vitest (codecs, win-rate, share choice) + Playwright social specs. Docs: PLAN
(Stage 8 done + refinements + TODO-5), ARCHITECTURE, FUNCTIONAL(+ru), UI_DESIGN,
TESTING, module READMEs.

ui/README.md

@@ -7,8 +7,10 @@ platform webviews and packageable to native via Capacitor.
 Stage 7 ships the **playable slice**: sign in (guest / email), the "my games" lobby,
 auto-match, the board (place tiles by drag or tap, pass, exchange, resign), hint,
 word-check + complaint, per-game chat and nudge, the live in-app stream, i18n (en/ru),
-theme, and a read-only profile. Friends/blocks, friend-game invitations, profile
-editing, the stats screen and the history/GCG viewer are Stage 8.
+theme, and the profile. **Stage 8** adds friends/blocks (with one-time friend codes),
+friend-game invitations, profile editing + email binding, the statistics screen, the
+lobby notification badge, and the in-game history + GCG export (share or download,
+finished games only).
 
 ## Scripts
 
@@ -60,10 +62,10 @@ runtime; the Telegram SDK itself is wired in the Telegram stage.
 ```
 src/
   lib/         model, client facade, transport (+ mock), codec, board replay,
-               placement state machine, premiums, i18n, theme, session, router, app store
-  components/  Header, Modal, Toast
-  screens/     Login, Lobby, NewGame, Profile, Settings, About
+               placement state machine, premiums, stats, share, i18n, theme, session, router, app store
+  components/  Header, Menu (+ badge), Modal, Toast, TabBar, Screen
+  screens/     Login, Lobby, NewGame, Profile, Settings, About, Friends, Stats
   game/        Game, Board, Rack, Controls, MakeMove, Chat
   gen/         committed edge codegen (FlatBuffers + Connect)
-e2e/           Playwright smoke (mock)
+e2e/           Playwright smoke + social specs (mock)
 ```