feat: implement dashboard ban overview (Stage 5)

- Add ban_service reading fail2ban SQLite DB via read-only aiosqlite
- Add geo_service resolving IPs via ip-api.com with 10k in-memory cache
- Add GET /api/dashboard/bans and GET /api/dashboard/accesses endpoints
- Add TimeRange, DashboardBanItem, DashboardBanListResponse, AccessListItem,
  AccessListResponse models in models/ban.py
- Build BanTable component (Fluent UI DataGrid) with bans/accesses modes,
  pagination, loading/error/empty states, and ban-count badges
- Build useBans hook managing time-range and pagination state
- Update DashboardPage: status bar + time-range toolbar + tab switcher
- Add 37 new backend tests (ban service, geo service, dashboard router)
- All 141 tests pass; ruff/mypy --strict/tsc --noEmit clean

frontend/src/api/dashboard.ts

@@ -1,20 +1,68 @@
 /**
  * Dashboard API module.
  *
- * Wraps the `GET /api/dashboard/status` endpoint.
+ * Wraps `GET /api/dashboard/status`, `GET /api/dashboard/bans`, and
+ * `GET /api/dashboard/accesses`.
  */
 
 import { get } from "./client";
 import { ENDPOINTS } from "./endpoints";
+import type { AccessListResponse, DashboardBanListResponse, TimeRange } from "../types/ban";
 import type { ServerStatusResponse } from "../types/server";
 
 /**
  * Fetch the cached fail2ban server status from the backend.
  *
- * @returns The server status response containing ``online``, ``version``,
- *   ``active_jails``, ``total_bans``, and ``total_failures``.
+ * @returns The server status response containing `online`, `version`,
+ *   `active_jails`, `total_bans`, and `total_failures`.
  * @throws {ApiError} When the server returns a non-2xx status.
  */
 export async function fetchServerStatus(): Promise<ServerStatusResponse> {
   return get<ServerStatusResponse>(ENDPOINTS.dashboardStatus);
 }
+
+/**
+ * Fetch a paginated ban list for the selected time window.
+ *
+ * @param range    - Time-range preset: `"24h"`, `"7d"`, `"30d"`, or `"365d"`.
+ * @param page     - 1-based page number (default `1`).
+ * @param pageSize - Items per page (default `100`).
+ * @returns Paginated {@link DashboardBanListResponse}.
+ * @throws {ApiError} When the server returns a non-2xx status.
+ */
+export async function fetchBans(
+  range: TimeRange,
+  page = 1,
+  pageSize = 100,
+): Promise<DashboardBanListResponse> {
+  const params = new URLSearchParams({
+    range,
+    page: String(page),
+    page_size: String(pageSize),
+  });
+  return get<DashboardBanListResponse>(`${ENDPOINTS.dashboardBans}?${params.toString()}`);
+}
+
+/**
+ * Fetch a paginated access list (individual matched log lines) for the
+ * selected time window.
+ *
+ * @param range    - Time-range preset.
+ * @param page     - 1-based page number (default `1`).
+ * @param pageSize - Items per page (default `100`).
+ * @returns Paginated {@link AccessListResponse}.
+ * @throws {ApiError} When the server returns a non-2xx status.
+ */
+export async function fetchAccesses(
+  range: TimeRange,
+  page = 1,
+  pageSize = 100,
+): Promise<AccessListResponse> {
+  const params = new URLSearchParams({
+    range,
+    page: String(page),
+    page_size: String(pageSize),
+  });
+  return get<AccessListResponse>(`/api/dashboard/accesses?${params.toString()}`);
+}
+