Stage 9: ban history — backend service, router, frontend history page

- history.py models: HistoryBanItem, HistoryListResponse, IpTimelineEvent, IpDetailResponse
- history_service.py: list_history() with dynamic WHERE clauses (range/jail/ip
  prefix/all-time), get_ip_detail() with timeline aggregation
- history.py router: GET /api/history + GET /api/history/{ip} (404 for unknown)
- Fixed latent bug in ban_service._parse_data_json: json.loads('null') -> None
  -> AttributeError; now checks isinstance(parsed, dict) before assigning obj
- 317 tests pass (27 new), ruff + mypy clean (46 files)
- types/history.ts, api/history.ts, hooks/useHistory.ts created
- HistoryPage.tsx: filter bar (time range/jail/IP), DataGrid table,
  high-ban-count row highlighting, per-IP IpDetailView with timeline,
  pagination
- Frontend tsc + ESLint clean (0 errors/warnings)
- Tasks.md Stage 9 marked done

frontend/src/hooks/useHistory.ts

@@ -0,0 +1,111 @@
+/**
+ * `useHistory` hook — fetches and manages ban history data.
+ */
+
+import { useCallback, useEffect, useRef, useState } from "react";
+import { fetchHistory, fetchIpHistory } from "../api/history";
+import type {
+  HistoryBanItem,
+  HistoryQuery,
+  IpDetailResponse,
+} from "../types/history";
+
+// ---------------------------------------------------------------------------
+// useHistory — paginated list
+// ---------------------------------------------------------------------------
+
+export interface UseHistoryResult {
+  items: HistoryBanItem[];
+  total: number;
+  page: number;
+  loading: boolean;
+  error: string | null;
+  setPage: (page: number) => void;
+  refresh: () => void;
+}
+
+export function useHistory(query: HistoryQuery = {}): UseHistoryResult {
+  const [items, setItems] = useState<HistoryBanItem[]>([]);
+  const [total, setTotal] = useState(0);
+  const [page, setPage] = useState(query.page ?? 1);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const abortRef = useRef<AbortController | null>(null);
+
+  const load = useCallback((): void => {
+    abortRef.current?.abort();
+    abortRef.current = new AbortController();
+    setLoading(true);
+    setError(null);
+
+    fetchHistory({ ...query, page })
+      .then((resp) => {
+        setItems(resp.items);
+        setTotal(resp.total);
+      })
+      .catch((err: unknown) => {
+        if (err instanceof Error && err.name !== "AbortError") {
+          setError(err.message);
+        }
+      })
+      .finally((): void => {
+        setLoading(false);
+      });
+  }, [query, page]);
+
+  useEffect((): (() => void) => {
+    load();
+    return (): void => {
+      abortRef.current?.abort();
+    };
+  }, [load]);
+
+  return { items, total, page, loading, error, setPage, refresh: load };
+}
+
+// ---------------------------------------------------------------------------
+// useIpHistory — per-IP detail
+// ---------------------------------------------------------------------------
+
+export interface UseIpHistoryResult {
+  detail: IpDetailResponse | null;
+  loading: boolean;
+  error: string | null;
+  refresh: () => void;
+}
+
+export function useIpHistory(ip: string): UseIpHistoryResult {
+  const [detail, setDetail] = useState<IpDetailResponse | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const abortRef = useRef<AbortController | null>(null);
+
+  const load = useCallback((): void => {
+    abortRef.current?.abort();
+    abortRef.current = new AbortController();
+    setLoading(true);
+    setError(null);
+
+    fetchIpHistory(ip)
+      .then((resp) => {
+        setDetail(resp);
+      })
+      .catch((err: unknown) => {
+        if (err instanceof Error && err.name !== "AbortError") {
+          setError(err.message);
+        }
+      })
+      .finally((): void => {
+        setLoading(false);
+      });
+  }, [ip]);
+
+  useEffect((): (() => void) => {
+    load();
+    return (): void => {
+      abortRef.current?.abort();
+    };
+  }, [load]);
+
+  return { detail, loading, error, refresh: load };
+}