Block BitTorrent on the server

- awg-ctrl: optional nft table awg_torrent (GET/PUT /api/torrent, off by
  default). A connection is judged by its first packets, like Xray's
  sniffing: DHT, UDP trackers, uTP SYN, and with @ih support the plain
  TCP handshake and HTTP announce. A match marks the connection in
  conntrack and drops it whole; without @ih only the UDP part is used
- devices that tried are kept in a 10-minute set and flagged as
  "torrent" in user and device stats; with shaping on they sit in the
  background class while the flag lasts
- metrics: awg_torrent_block_enabled/active, awg_torrent_blocked_total,
  awg_torrent_devices and per-peer awg_peer_torrent
- panel: "Торренты" section in server settings, "торренты" chip on users
  and devices; Save sends only what changed

awg-ui/src/components/TorrentChip.tsx

@@ -0,0 +1,14 @@
+// Copyright (c) 2026 Ivan Vasilev
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+// Пометка «торренты»: устройство за последние 10 минут пыталось открыть торрент-соединение, и оно
+// было заблокировано. Без флага (блокировка выключена или awg-ctrl старше) чип не показываем.
+export default function TorrentChip({ torrent }: { torrent?: boolean }) {
+    if (!torrent) return null;
+    return (
+        <span className="tip-wrap" data-tip="За последние 10 минут пыталось качать торренты: соединения заблокированы, а при делении канала устройство в фоновом приоритете">
+            <span className="chip chip--error"><span className="chip-dot" />торренты</span>
+        </span>
+    );
+}