Finish fine-grained ACL across remaining admin pages and actions.

Replace leftover requireStaff gates with module PERMS, drop hardcoded room rank thresholds, and expand contract tests so admin mutations cannot regress to dashboard-only checks.

Co-authored-by: Cursor <[email protected]>

src/actions/admin-vpn.ts

@@ -2,7 +2,8 @@
 
 import { revalidatePath } from "next/cache";
 import { redirect } from "next/navigation";
-import { requireStaff } from "@/lib/admin/guard";
+import { requirePermission } from "@/lib/admin/guard";
+import { PERMS } from "@/lib/permissions";
 import { prisma } from "@/lib/prisma";
 import { siteSettings } from "@/lib/services/site-settings";
 import { logStaffActivity } from "@/lib/services/staff-activity";
@@ -28,7 +29,7 @@ async function writeSetting(
 }
 
 export async function saveVpn(formData: FormData): Promise<void> {
-	const staff = await requireStaff();
+	const staff = await requirePermission(PERMS.SETTINGS_EDIT);
 
 	// Toggle: an unchecked checkbox submits nothing, so absence === disabled.
 	const enabled =