Reapply "Add missing admin action files and navigation links"

This reverts commit 4d515bc400.

src/lib/access-guard.ts

@@ -22,8 +22,7 @@ function isExempt(path: string): boolean {
 export async function enforceSiteAccess(): Promise<void> {
   const h = await headers();
   const path = h.get("x-pathname") ?? "/";
-  const ip =
-    h.get("x-real-client-ip") ?? h.get("x-forwarded-for")?.split(",")[0]?.trim() ?? "0.0.0.0";
+  const ip = h.get("x-real-client-ip") ?? h.get("x-forwarded-for")?.split(",")[0]?.trim() ?? "0.0.0.0";
 
   // Abuse/DDoS guard: count this request and block flooding IPs (no-op unless
   // enabled in settings). Best-effort — never let it throw past the guard.