feat(agent): send stream port and IPs in register request

Include StreamPort, LanIP, and TailscaleIP in RegisterRequest so the
server knows the agent's stream endpoints from the moment it registers,
not just after the first heartbeat. Align HeartbeatRequest field order
with RegisterRequest for consistency.

internal/agent/daemon.go

@@ -94,6 +94,9 @@ func (d *Daemon) Register(ctx context.Context) error {
 		Arch:        runtime.GOARCH,
 		Version:     d.cfg.Version,
 		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

internal/agent/types.go

@@ -15,6 +15,9 @@ type RegisterRequest 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"`
 }
 
 // RegisterResponse is returned by the server after registration.
@@ -51,8 +54,8 @@ type UsenetServerInfo struct {
 type HeartbeatRequest struct {
 	AgentID        string `json:"agentId"`
 	Name           string `json:"name,omitempty"`
-	Version        string `json:"version,omitempty"`
 	OS             string `json:"os,omitempty"`
+	Version        string `json:"version,omitempty"`
 	DownloadDir    string `json:"downloadDir,omitempty"`
 	DiskFreeBytes  int64  `json:"diskFreeBytes,omitempty"`
 	DiskTotalBytes int64  `json:"diskTotalBytes,omitempty"`