Stage 7 (wip): tests + UI CI

- Vitest units: board replay, placement machine, premium parity, i18n key parity, FlatBuffers codec round-trips (19 tests)
- Playwright smoke (mock transport): guest -> lobby -> board -> place tile -> preview
- ui-test.yaml workflow: check/unit/build + bundle-size budget (67.5KB gzip < 100KB) + chromium e2e
- gateway transcode tests for games.list (seat display_name), pass, hint
- backend integration test for game.ListForAccount

ui/scripts/bundle-size.mjs

@@ -0,0 +1,21 @@
+// Bundle-size budget gate. Sums the gzipped size of the built app JS and fails if it
+// exceeds the budget — a guard against an accidental heavy dependency. The real
+// transport build is ~69 KB gzip today; the budget leaves headroom.
+import { readdirSync, readFileSync } from 'node:fs';
+import { gzipSync } from 'node:zlib';
+
+const BUDGET = 100 * 1024; // gzip bytes for app JS
+const dir = 'dist/assets';
+
+let total = 0;
+for (const f of readdirSync(dir)) {
+  if (!f.endsWith('.js')) continue;
+  const gz = gzipSync(readFileSync(`${dir}/${f}`)).length;
+  total += gz;
+  console.log(`${f}: ${(gz / 1024).toFixed(1)} KB gzip`);
+}
+console.log(`total app JS: ${(total / 1024).toFixed(1)} KB gzip (budget ${BUDGET / 1024} KB)`);
+if (total > BUDGET) {
+  console.error('bundle exceeds size budget');
+  process.exit(1);
+}