Wires anacrolix/torrent's built-in webtorrent package so a browser
running webtorrent.js can fetch pieces from this CLI via WebRTC data
channels. The daemon stays the seeder; we never relay bytes through
TorrentClaw infrastructure — same legal posture as today.
Changes:
- internal/config: new [downloads.webrtc] section
(enabled/trackers/stun_servers/turn_servers/turn_user/turn_pass).
Disabled by default, opt-in via config.toml. When enabled but
trackers / STUN slices are empty, defaults are reapplied on Load() so
users get a working setup with a single `enabled = true`.
- internal/engine: TorrentConfig gains WebRTCEnabled / WebRTCTrackers
/ ICEServers; NewTorrentDownloader populates ClientConfig.ICEServerList
and forces NoUpload=false when WebRTC is on (browsers can't pull
otherwise). buildMagnet now accepts variadic extra trackers and the
downloader method prepends WSS trackers so anacrolix's
webtorrent.TrackerClient picks them up first.
- internal/engine/webrtc.go: BuildICEServers helper converts the TOML
WebRTCConfig into []webrtc.ICEServer with shared TURN credentials.
- internal/cmd/daemon.go + download.go: pass WebRTC config through to
the engine.
Tests (8 new, all green; full suite 0 lint issues, 0 vet):
- buildMagnet free function: defaults-only, with extras, trim+empty-skip
- downloader method: WebRTC disabled keeps WSS out, enabled prepends them
- BuildICEServers: nil when disabled, STUN-only path, TURN+credentials
- NewTorrentDownloader: full WebRTC-enabled construction (logs WebRTC
peer enabled, magnet contains wss://tracker.torrentclaw.com)
End-to-end smoke (browser ↔ unarr peer transfer) is deferred to a
manual test once tracker.torrentclaw.com WSS is live.
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