Revert "Update management-auth.ts"

This reverts commit 0dd50c0375.

src/services/management/management-auth.ts

@@ -40,8 +40,7 @@ export async function clearManagerSession() {
 export async function isManagerAuthenticated() {
   const config = getManagerConfig();
   if (!config.authSecret) return false;
-  const rawValue = (await cookies()).get(COOKIE_NAME)?.value;
-  const value = rawValue ? decodeURIComponent(rawValue) : undefined;
+  const value = (await cookies()).get(COOKIE_NAME)?.value;
   if (!value) return false;
   const separator = value.lastIndexOf(".");
   if (separator < 1) return false;