Update README with project details and setup instructions; add data directories to .gitignore

run.cmd

@@ -0,0 +1,30 @@
+@echo off
+rem Starts the whole stack through Aspire: the API, then npm install and the Vite dev server.
+rem The dashboard URL (with its login token) is printed a few seconds after launch.
+
+setlocal
+cd /d "%~dp0"
+
+where dotnet >nul 2>&1 || (
+    echo The .NET SDK was not found on PATH. Install .NET 10 from https://dotnet.microsoft.com/download
+    goto :failed
+)
+
+where node >nul 2>&1 || (
+    echo Node.js was not found on PATH. The web client needs Node 20 or newer.
+    goto :failed
+)
+
+dotnet run --project src\TheLivingWorld.AppHost %*
+if errorlevel 1 goto :failed
+
+endlocal
+exit /b 0
+
+:failed
+echo.
+echo Startup failed. See the output above.
+rem Keep the window open when this was launched from Explorer rather than a console.
+if /i "%~1"=="" pause
+endlocal
+exit /b 1