Reapply "Add missing admin action files and navigation links"

This reverts commit 4d515bc400.

src/actions/admin-alerts.ts

@@ -13,7 +13,9 @@ import { rcon } from "@/lib/services/rcon";
 export async function sendHotelAlert(formData: FormData): Promise<void> {
   await requireStaff();
 
-  const message = String(formData.get("message") ?? "").trim().slice(0, 1000);
+  const message = String(formData.get("message") ?? "")
+    .trim()
+    .slice(0, 1000);
   if (!message) return;
 
   try {