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/vite.config.ts

@@ -0,0 +1,29 @@
+import { defineConfig } from 'vite';
+import { svelte } from '@sveltejs/vite-plugin-svelte';
+
+// The edge Connect service is scrabble.edge.v1.Gateway; the gateway serves it over
+// h2c on :8081 by default. In dev we proxy the RPC path so the browser (which can
+// not speak h2c directly) talks to the dev server on the same origin. In `mock`
+// mode the app runs entirely against an in-memory fake transport — no gateway,
+// no backend, no Postgres — which is what `pnpm start` launches.
+const RPC_PREFIX = '/scrabble.edge.v1.Gateway';
+
+export default defineConfig(({ mode }) => ({
+  plugins: [svelte()],
+  server: {
+    port: 5173,
+    proxy:
+      mode === 'mock'
+        ? undefined
+        : {
+            [RPC_PREFIX]: {
+              target: process.env.GATEWAY_URL || 'http://localhost:8081',
+              changeOrigin: true,
+            },
+          },
+  },
+  build: {
+    target: 'es2022',
+    sourcemap: true,
+  },
+}));