I think unix signals are a bit lacking for your use case now. I’d consider having the daemon also have a web interface that you could then have the web server message. You mention systemd also, so could also consider MQ message queuing or D-Bus. Getting these to scale across computers isn’t as simple, hence my http suggestion initially. HTTP should also then be OS agnostic
WSL2 with VSCode is really common. Windows Terminal is actually good. I use Ubuntu at work, and run Docker community edition and Vim. Firefox in the windows instance. Biggest issue is always the corporate firewall, good luck!