fix(torrents): harden post-release lifecycle boundaries

- make Torrent journals and metadata caches atomic across platforms
- reject unsafe Torrent cache and web-seed inputs
- validate magnet trackers through the shared policy
- preserve embedded web seeds during explicit installation
- correct 1-based Torrent file indices in renderer state and Properties UI

src-tauri/Cargo.lock

@@ -1441,6 +1441,7 @@ dependencies = [
  "url",
  "uuid",
  "windows-native-keyring-store",
+ "windows-sys 0.61.2",
  "zbus-secret-service-keyring-store",
 ]