ci(e2e): build through the package script so prebuild assets exist

The e2e job called next build directly, skipping the prebuild hook
that generates the service-worker version stamp and the static i18n
catalog assets — fourteen specs timed out waiting on a UI that never
got its catalog.

.github/workflows/e2e.yml

@@ -69,7 +69,11 @@ jobs:
 
       - run: pnpm exec playwright install --with-deps chromium
 
-      - run: pnpm exec next build
+      # `pnpm build` (not bare `next build`): the prebuild hook generates
+      # the versioned service-worker stamp AND the static i18n catalog
+      # assets (public/i18n/<locale>.js) the client boots from — without
+      # them every UI interaction waits on missing catalogs.
+      - run: pnpm build
 
       # Client-bundle budget gate — rides this job because it is the one
       # place CI already has a production build on disk. Catches the