Node 22+ everywhere, LF text on Windows checkouts, CI actions v7

- Node minimum is 22 in package.json engines, the start scripts, the service installer, setup and doctor,
  matching the README, the release notes and the CI matrix (22 / 24).
- .gitattributes: CSS, HTML, JSON, Markdown and YAML check out with LF, so `node --test` on Windows matches the
  CSS rules the UI tests read; the Windows test step is no longer continue-on-error.
- CI: actions/checkout@v7 and actions/setup-node@v7 (Node 24 runtime).

scripts/start-windows.bat

@@ -10,7 +10,7 @@ cd /d "%~dp0.."
 
 where node >nul 2>nul
 if errorlevel 1 goto :nonode
-node -e "process.exit(Number(process.versions.node.split('.')[0])>=18?0:1)"
+node -e "process.exit(Number(process.versions.node.split('.')[0])>=22?0:1)"
 if errorlevel 1 goto :oldnode
 
 if not exist "node_modules\ws\package.json" (
@@ -25,7 +25,7 @@ exit /b 0
 
 :nonode
 echo.
-echo 未找到 Node.js（需要 18 或更高，推荐 22 LTS）。Node.js not found.
+echo 未找到 Node.js（需要 22 或更高，22 / 24 LTS）。Node.js not found.
 echo.
 echo   方法一：在 PowerShell 或命令提示符中运行
 echo       winget install OpenJS.NodeJS.LTS
@@ -38,7 +38,7 @@ exit /b 1
 
 :oldnode
 echo.
-for /f "delims=" %%v in ('node -v') do echo 当前 Node.js 版本 %%v 太旧，需要 18 或更高（推荐 22 LTS）。
+for /f "delims=" %%v in ('node -v') do echo 当前 Node.js 版本 %%v 太旧，需要 22 或更高（22 / 24 LTS）。
 echo   升级：winget upgrade OpenJS.NodeJS.LTS   或   https://nodejs.org/zh-cn/download
 echo.
 pause