fix: add AbortController and unmount guard to useIpLookup hook

- Add AbortController to cancel pending IP lookups when component unmounts
- Prevent state updates on unmounted components by checking abort signal before setState calls
- Add useEffect cleanup that aborts pending requests on unmount
- Update lookupIp API function to accept optional AbortSignal parameter
- Converts callback-based fetch to async/await pattern for better control flow
- Aligns with other API functions that already support abort signals (fetchJails, fetchJailBannedIps)

Fixes TASK-ABORT-04

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/api/jails.ts

@@ -237,11 +237,12 @@ export async function unbanAllBans(): Promise<UnbanAllResponse> {
  * Look up ban status and geo-location for an IP address.
  *
  * @param ip - IP address to look up.
+ * @param signal - Optional abort signal for request cancellation.
  * @returns An {@link IpLookupResponse} with ban history and geo info.
  * @throws {ApiError} On non-2xx responses (400 for invalid IP).
  */
-export async function lookupIp(ip: string): Promise<IpLookupResponse> {
-  return get<IpLookupResponse>(ENDPOINTS.geoLookup(ip));
+export async function lookupIp(ip: string, signal?: AbortSignal): Promise<IpLookupResponse> {
+  return get<IpLookupResponse>(ENDPOINTS.geoLookup(ip), signal);
 }
 
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