Add AbortSignal support to API functions for request cancellation

Add optional signal?: AbortSignal parameter to all API GET functions so they can be
cancelled when components unmount. This prevents state-update warnings and wasted
resources.

Changes:
- frontend/src/api/history.ts: fetchHistory, fetchIpHistory
- frontend/src/api/map.ts: fetchBansByCountry
- frontend/src/api/jails.ts: fetchJails, fetchActiveBans
- frontend/src/api/config.ts: fetchJailConfig, fetchInactiveJails, fetchJailConfigFiles,
  fetchFilterFiles (threads signal through fetchFilters), fetchFilterFile, fetchActionFiles,
  fetchActionFile
- frontend/src/api/blocklist.ts: fetchImportLog, previewBlocklist

Updated all calling hooks to pass the abort signal from their controllers:
- useHistory, useIpHistory
- useMapData
- useActiveBans
- useJails
- useConfigActiveStatus (fetchJails and fetchJailConfigs)
- useJailAdmin (fetchInactiveJails)
- useJailConfigDetail (fetchJailConfig)
- useImportLog (fetchImportLog)
- useBlocklists (previewBlocklist with AbortController)

Updated Docs/Web-Development.md to document the convention.

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

frontend/src/hooks/useHistory.ts

@@ -39,7 +39,7 @@ export function useHistory(query: HistoryQuery = {}): UseHistoryResult {
     setLoading(true);
     setError(null);
 
-    fetchHistory({ ...query, page })
+    fetchHistory({ ...query, page }, abortRef.current.signal)
       .then((resp) => {
         setItems(resp.items);
         setTotal(resp.total);
@@ -85,7 +85,7 @@ export function useIpHistory(ip: string): UseIpHistoryResult {
     setLoading(true);
     setError(null);
 
-    fetchIpHistory(ip)
+    fetchIpHistory(ip, abortRef.current.signal)
       .then((resp) => {
         setDetail(resp);
       })