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/App.svelte

@@ -0,0 +1,47 @@
+<script lang="ts">
+  import { onMount } from 'svelte';
+  import { app, bootstrap } from './lib/app.svelte';
+  import { router } from './lib/router.svelte';
+  import { t } from './lib/i18n/index.svelte';
+  import Toast from './components/Toast.svelte';
+  import Login from './screens/Login.svelte';
+  import Lobby from './screens/Lobby.svelte';
+  import NewGame from './screens/NewGame.svelte';
+  import Profile from './screens/Profile.svelte';
+  import Settings from './screens/Settings.svelte';
+  import About from './screens/About.svelte';
+  import Game from './game/Game.svelte';
+
+  onMount(() => {
+    void bootstrap();
+  });
+</script>
+
+{#if !app.ready}
+  <div class="splash">{t('common.loading')}</div>
+{:else if router.route.name === 'login'}
+  <Login />
+{:else if router.route.name === 'new'}
+  <NewGame />
+{:else if router.route.name === 'game'}
+  <Game id={router.route.params.id} />
+{:else if router.route.name === 'profile'}
+  <Profile />
+{:else if router.route.name === 'settings'}
+  <Settings />
+{:else if router.route.name === 'about'}
+  <About />
+{:else}
+  <Lobby />
+{/if}
+
+<Toast />
+
+<style>
+  .splash {
+    height: 100%;
+    display: grid;
+    place-items: center;
+    color: var(--text-muted);
+  }
+</style>