Stage 7 (wip): UI shell, libs, mock transport, screens (lobby->game), e2e smoke

- plain Svelte 5 + TS + Vite (no SvelteKit); CSS-token design system (Telegram-ready), hash router, IndexedDB session
- pure libs: domain model, premium/value maps ported from solver, board replay, placement state machine, i18n en/ru
- in-memory mock transport + seed data; pnpm start runs lobby->active game->board with no backend
- board: pointer-drag + tap placement, MakeMove (popup / 1s-hold commit), two-state zoom, blank chooser, exchange, hint, word-check, chat
- Playwright smoke (mock) green; svelte-check clean; mock bundle ~37 KB gzip

ui/src/lib/transport.ts

@@ -0,0 +1,36 @@
+// Placeholder for the real Connect-web + FlatBuffers transport, wired in the edge
+// codegen task. Until then, selecting a non-mock mode surfaces a clear error instead
+// of failing silently. The mock (lib/mock) backs `pnpm start`.
+
+import type { GatewayClient } from './client';
+import { GatewayError } from './client';
+
+export function createTransport(_baseUrl: string): GatewayClient {
+  const ni = (): never => {
+    throw new GatewayError('unavailable', 'real transport not wired yet');
+  };
+  return {
+    setToken: () => {},
+    authGuest: ni,
+    authEmailRequest: ni,
+    authEmailLogin: ni,
+    profileGet: ni,
+    gamesList: ni,
+    lobbyEnqueue: ni,
+    lobbyPoll: ni,
+    gameState: ni,
+    gameHistory: ni,
+    submitPlay: ni,
+    pass: ni,
+    exchange: ni,
+    resign: ni,
+    hint: ni,
+    evaluate: ni,
+    checkWord: ni,
+    complaint: ni,
+    chatPost: ni,
+    chatList: ni,
+    nudge: ni,
+    subscribe: ni,
+  };
+}