Delete the Qt host (src/, cmake/, CMakeLists.txt, find-qt.bat, check-setup.bat,
build.bat, deploy.bat) now that the Avalonia host in host/ covers it on the same
dotnet toolchain. Add a self-hosted host-build CI job and a host README, and
rewrite the top-level README for the C# server + Avalonia host layout.
Adds an admin-protocol client (token-authed TCP JSON on 127.0.0.1:AdminPort,
reusing the server's .admin-token) that polls connected players and status
every 3s, plus Kick/Ban on the selected player and a players/uptime readout.
Cross-platform C# GUI to replace the Qt/C++ Host GUI, on the same dotnet
toolchain as the server. MVP: load/save commonwealth-server.json, Start/Stop
the CommonwealthOnline.Server process (published exe, then dll, then source
run), and stream its output to a live log. Themed to the Commonwealth Online
brand (near-black + amber). Builds clean on net8.0.
Next: player list + kick/ban via the admin port, then retire the Qt host.