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/components/BanTable.tsx

@@ -27,7 +27,7 @@ import {
 import { PageEmpty, PageError, PageLoading } from "./PageFeedback";
 import { ChevronLeftRegular, ChevronRightRegular } from "@fluentui/react-icons";
 import { useBans } from "../hooks/useBans";
-import type { DashboardBanItem, TimeRange } from "../types/ban";
+import type { DashboardBanItem, TimeRange, BanOriginFilter } from "../types/ban";
 
 // ---------------------------------------------------------------------------
 // Types
@@ -40,6 +40,11 @@ interface BanTableProps {
    * Changing this value triggers a re-fetch.
    */
   timeRange: TimeRange;
+  /**
+   * Active origin filter — controlled by the parent `DashboardPage`.
+   * Changing this value triggers a re-fetch and resets to page 1.
+   */
+  origin?: BanOriginFilter;
 }
 
 // ---------------------------------------------------------------------------
@@ -159,6 +164,18 @@ function buildBanColumns(styles: ReturnType<typeof useStyles>): TableColumnDefin
       renderHeaderCell: () => "Jail",
       renderCell: (item) => <Text size={200}>{item.jail}</Text>,
     }),
+    createTableColumn<DashboardBanItem>({
+      columnId: "origin",
+      renderHeaderCell: () => "Origin",
+      renderCell: (item) => (
+        <Badge
+          appearance="tint"
+          color={item.origin === "blocklist" ? "brand" : "informative"}
+        >
+          {item.origin === "blocklist" ? "Blocklist" : "Selfblock"}
+        </Badge>
+      ),
+    }),
     createTableColumn<DashboardBanItem>({
       columnId: "ban_count",
       renderHeaderCell: () => "Bans",
@@ -183,10 +200,11 @@ function buildBanColumns(styles: ReturnType<typeof useStyles>): TableColumnDefin
  * Data table for the dashboard ban-list view.
  *
  * @param props.timeRange - Active time-range preset from the parent page.
+ * @param props.origin    - Active origin filter from the parent page.
  */
-export function BanTable({ timeRange }: BanTableProps): React.JSX.Element {
+export function BanTable({ timeRange, origin = "all" }: BanTableProps): React.JSX.Element {
   const styles = useStyles();
-  const { banItems, total, page, setPage, loading, error, refresh } = useBans(timeRange);
+  const { banItems, total, page, setPage, loading, error, refresh } = useBans(timeRange, origin);
 
   const banColumns = buildBanColumns(styles);