feat(stream): persistent stream server with file swapping

internal/agent/daemon.go

@@ -20,6 +20,9 @@ type DaemonConfig struct {
 	DownloadDir       string
 	PollInterval      time.Duration
 	HeartbeatInterval time.Duration
+	StreamPort        int    // port for the HTTP stream server (reported in heartbeat)
+	LanIP             string // LAN IP (reported in heartbeat for stream URL resolution)
+	TailscaleIP       string // Tailscale IP (reported in heartbeat for stream URL resolution)
 }
 
 // Daemon manages the main loop: register, heartbeat, poll tasks.
@@ -211,6 +214,9 @@ func (d *Daemon) heartbeat(ctx context.Context) {
 		Version:     d.cfg.Version,
 		OS:          runtime.GOOS,
 		DownloadDir: d.cfg.DownloadDir,
+		StreamPort:  d.cfg.StreamPort,
+		LanIP:       d.cfg.LanIP,
+		TailscaleIP: d.cfg.TailscaleIP,
 	}
 	if free, total, err := DiskInfo(d.cfg.DownloadDir); err == nil {
 		req.DiskFreeBytes = free
@@ -297,6 +303,12 @@ func (d *Daemon) handleEvent(event ServerEvent) {
 	}
 }
 
+// UpdateStreamPort updates the stream port reported in heartbeats.
+// Called after the persistent stream server binds (actual port may differ from configured).
+func (d *Daemon) UpdateStreamPort(port int) {
+	d.cfg.StreamPort = port
+}
+
 // TriggerPoll requests an immediate task poll cycle.
 // Used when a resume event is received to pick up re-pending tasks faster.
 func (d *Daemon) TriggerPoll() {

internal/agent/transport_ws.go

@@ -178,6 +178,7 @@ func (t *WSTransport) SendProgress(_ context.Context, update StatusUpdate) (*Sta
 		FileName        string `json:"fileName,omitempty"`
 		FilePath        string `json:"filePath,omitempty"`
 		StreamURL       string `json:"streamUrl,omitempty"`
+		StreamReady     bool   `json:"streamReady,omitempty"`
 		ErrorMessage    string `json:"errorMessage,omitempty"`
 	}{
 		Type:            "progress",
@@ -192,6 +193,7 @@ func (t *WSTransport) SendProgress(_ context.Context, update StatusUpdate) (*Sta
 		FileName:        update.FileName,
 		FilePath:        update.FilePath,
 		StreamURL:       update.StreamURL,
+		StreamReady:     update.StreamReady,
 		ErrorMessage:    update.ErrorMessage,
 	}
 

internal/agent/types.go

@@ -56,6 +56,9 @@ type HeartbeatRequest struct {
 	DownloadDir    string `json:"downloadDir,omitempty"`
 	DiskFreeBytes  int64  `json:"diskFreeBytes,omitempty"`
 	DiskTotalBytes int64  `json:"diskTotalBytes,omitempty"`
+	StreamPort     int    `json:"streamPort,omitempty"`
+	LanIP          string `json:"lanIp,omitempty"`
+	TailscaleIP    string `json:"tailscaleIp,omitempty"`
 }
 
 // Task represents a download task claimed from the server.
@@ -107,6 +110,7 @@ type StatusUpdate struct {
 	FileName        string `json:"fileName,omitempty"`
 	FilePath        string `json:"filePath,omitempty"`
 	StreamURL       string `json:"streamUrl,omitempty"`
+	StreamReady     bool   `json:"streamReady,omitempty"`
 	ErrorMessage    string `json:"errorMessage,omitempty"`
 }