FileSystem.php isRelativePath() compatibility for windows

src/ZM/Store/FileSystem.php

@@ -70,6 +70,10 @@ class FileSystem
      */
     public static function isRelativePath(string $path): bool
     {
+        // 适配 Windows 的多盘符目录形式
+        if (DIRECTORY_SEPARATOR === '\\') {
+            return strlen($path) > 2 && ctype_alpha($path[0]) && $path[1] === ':';
+        }
         return strlen($path) > 0 && $path[0] !== '/';
     }