fix(agent/windows): named pipe Tailscale + hideWindow + logs

- Use Windows named pipe \.\pipe\studioe5-tailscaled instead of Unix socket
- Apply hideWindow to all child processes (tailscale, podman, docker, browser)
- Redirect agent logs to <data-dir>/agent.log and tailscaled logs to tailscaled.log
- Fix double tailscale/ tailscale dir path in startTailscaleAndReport
- Remove --operator=root on Windows
- Bump agent version to 0.3.1

agent/ui.go

@@ -61,6 +61,7 @@ func startUI(dataDir, nodeID, serverAddr string) {
 		w.WriteHeader(http.StatusNoContent)
 		go func() {
 			cmd := exec.Command(os.Args[0], os.Args[1:]...)
+			hideWindow(cmd)
 			cmd.Stdout = os.Stdout
 			cmd.Stderr = os.Stderr
 			cmd.Stdin = os.Stdin