fix(rpc): render canonical csrf token for clients

packages/dev-server/src/runtime.ts

@@ -1873,6 +1873,7 @@ export function createHandlers(deps: RuntimeDeps): Handlers {
       body: renderedBody,
       scripts,
       extraHead: [
+        `<meta name="wrnexus-csrf" content="${escapeHtml(pageCsrf)}" />`,
         preserve ? `<meta name="wrnexus-preserve" content="${preserve}" />` : "",
         pwaEnabled ? `<link rel="manifest" href="/site.webmanifest" />` : "",
         pwaEnabled ? `<meta name="mobile-web-app-capable" content="yes" />` : "",