chore: retain existing headers

Author: 43081j

modules/security-headers.ts

@@ -64,9 +64,11 @@ export default defineNuxtModule({
 
     // Other security headers via route rules (fine on all responses).
     nuxt.options.routeRules ??= {}
+    const wildCardRules = nuxt.options.routeRules['/**'];
     nuxt.options.routeRules['/**'] = {
-      ...nuxt.options.routeRules['/**'],
+      ...wildCardRules,
       headers: {
+        ...wildCardRules?.headers,
         'X-Content-Type-Options': 'nosniff',
         'X-Frame-Options': 'DENY',
         'Referrer-Policy': 'strict-origin-when-cross-origin',