fix(docker): three streaming/reliability bugs found in live docker test

funnel: urlPattern matched api.trycloudflare.com before the real quick-tunnel
URL. Cloudflared logs the control-plane endpoint early, so the agent was
advertising a dead URL. Tighten regex to require at least one hyphen — quick
tunnels are always multi-word (e.g. make-appointments-negotiation-blacks).
Covers with funnel_test.go regression test.

download(oneshot): progress reporter called /api/internal/agent/status with a
synthetic "oneshot-<hash>" task ID that is not a UUID, causing the server to
return 400 every 5 s for the entire download. Pass nil client to
NewProgressReporter for one-shot mode; flush/ReportFinal are no-ops when
reporter == nil so terminal output continues unchanged.

torrent: piece-completion SQLite DB (anacrolix) was created inside the download
dir (DataDir). On NFS/SMB mounts SQLite file locking times out, emitting a
warning and falling back to an ephemeral in-memory DB. Add PieceCompletionDir
to TorrentConfig; the daemon now passes config.DataDir() (agent state dir,
always local) so the DB stays off the network mount. One-shot download leaves
the field empty → harmless in-memory fallback as before.

internal/cmd/daemon.go

@@ -265,15 +265,16 @@ func runDaemonStart() error {
 
 	// Create torrent downloader
 	torrentDl, err := engine.NewTorrentDownloader(engine.TorrentConfig{
-		DataDir:         cfg.Download.Dir,
-		MetadataTimeout: metaTimeout,
-		StallTimeout:    stallTimeout,
-		MaxTimeout:      0,
-		MaxDownloadRate: maxDl,
-		MaxUploadRate:   maxUl,
-		ListenPort:      cfg.Download.ListenPort,
-		SeedEnabled:     false,
-		VPNTunnel:       vpnTunnel,
+		DataDir:            cfg.Download.Dir,
+		PieceCompletionDir: config.DataDir(), // keep piece-completion DB off NFS/SMB mounts
+		MetadataTimeout:    metaTimeout,
+		StallTimeout:       stallTimeout,
+		MaxTimeout:         0,
+		MaxDownloadRate:    maxDl,
+		MaxUploadRate:      maxUl,
+		ListenPort:         cfg.Download.ListenPort,
+		SeedEnabled:        false,
+		VPNTunnel:          vpnTunnel,
 	})
 	if err != nil {
 		return fmt.Errorf("create torrent downloader: %w", err)