Add origin field and filter for ban sources (Tasks 1 & 2)

- Task 1: Mark imported blocklist IP addresses
  - Add BanOrigin type and _derive_origin() to ban.py model
  - Populate origin field in ban_service list_bans() and bans_by_country()
  - BanTable and MapPage companion table show origin badge column
  - Tests: origin derivation in test_ban_service.py and test_dashboard.py

- Task 2: Add origin filter to dashboard and world map
  - ban_service: _origin_sql_filter() helper; origin param on list_bans()
    and bans_by_country()
  - dashboard router: optional origin query param forwarded to service
  - Frontend: BanOriginFilter type + BAN_ORIGIN_FILTER_LABELS in ban.ts
  - fetchBans / fetchBansByCountry forward origin to API
  - useBans / useMapData accept and pass origin; page resets on change
  - BanTable accepts origin prop; DashboardPage adds segmented filter
  - MapPage adds origin Select next to time-range picker
  - Tests: origin filter assertions in test_ban_service and test_dashboard

frontend/src/hooks/useBans.ts

@@ -7,7 +7,7 @@
 
 import { useCallback, useEffect, useRef, useState } from "react";
 import { fetchBans } from "../api/dashboard";
-import type { DashboardBanItem, TimeRange } from "../types/ban";
+import type { DashboardBanItem, TimeRange, BanOriginFilter } from "../types/ban";
 
 /** Items per page for the ban table. */
 const PAGE_SIZE = 100;
@@ -33,29 +33,33 @@ export interface UseBansResult {
 /**
  * Fetch and manage dashboard ban-list data.
  *
- * Automatically re-fetches when `timeRange` or `page` changes.
+ * Automatically re-fetches when `timeRange`, `origin`, or `page` changes.
  *
  * @param timeRange - Time-range preset that controls how far back to look.
+ * @param origin    - Origin filter (default `"all"`).
  * @returns Current data, pagination state, loading flag, and a `refresh`
  *   callback.
  */
-export function useBans(timeRange: TimeRange): UseBansResult {
+export function useBans(
+  timeRange: TimeRange,
+  origin: BanOriginFilter = "all",
+): UseBansResult {
   const [banItems, setBanItems] = useState<DashboardBanItem[]>([]);
   const [total, setTotal] = useState<number>(0);
   const [page, setPage] = useState<number>(1);
   const [loading, setLoading] = useState<boolean>(true);
   const [error, setError] = useState<string | null>(null);
 
-  // Reset page when time range changes.
+  // Reset page when time range or origin filter changes.
   useEffect(() => {
     setPage(1);
-  }, [timeRange]);
+  }, [timeRange, origin]);
 
   const doFetch = useCallback(async (): Promise<void> => {
     setLoading(true);
     setError(null);
     try {
-      const data = await fetchBans(timeRange, page, PAGE_SIZE);
+      const data = await fetchBans(timeRange, page, PAGE_SIZE, origin);
       setBanItems(data.items);
       setTotal(data.total);
     } catch (err: unknown) {
@@ -63,7 +67,7 @@ export function useBans(timeRange: TimeRange): UseBansResult {
     } finally {
       setLoading(false);
     }
-  }, [timeRange, page]);
+  }, [timeRange, page, origin]);
 
   // Stable ref to the latest doFetch so the refresh callback is always current.
   const doFetchRef = useRef(doFetch);