fix layout SSR translations and remediation follow-ups

packages/dev-server/src/runtime.ts

@@ -1815,7 +1815,14 @@ export function createHandlers(deps: RuntimeDeps): Handlers {
     if (isMobileRequest) body = revealMobileOnlyHtml(body);
 
     // i18n: resolve `{t:key}` / `t:attr` markers against the request language.
-    if (deps.i18n) body = translateHtml(body, ctx.t);
+    if (deps.i18n) {
+      body = translateHtml(body, ctx.t);
+      // renderDocument prefers the complete document template when one was
+      // rendered. Keep it in sync with the translated body; otherwise markers
+      // owned by document/page layouts are replaced by the stale pre-translation
+      // template even though page-only responses translate correctly.
+      if (documentTemplate) documentTemplate = body;
+    }
 
     // Point 3: only ship the JS this page actually uses.
     const scripts = collectScripts(body, deps.clientRuntimes, deps.navigation).map((script) =>