code_style: move platform-dependent code to SourceGit.Native.OS

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Converters/PathConverters.cs

@@ -1,6 +1,4 @@
-using System;
 using System.IO;
-
 using Avalonia.Data.Converters;
 
 namespace SourceGit.Converters
@@ -14,17 +12,6 @@ public static class PathConverters
             new(v => Path.GetDirectoryName(v) ?? "");
 
         public static readonly FuncValueConverter<string, string> RelativeToHome =
-            new(v =>
-            {
-                if (OperatingSystem.IsWindows())
-                    return v;
-
-                var home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
-                var prefixLen = home.EndsWith('/') ? home.Length - 1 : home.Length;
-                if (v.StartsWith(home, StringComparison.Ordinal))
-                    return $"~{v.AsSpan(prefixLen)}";
-
-                return v;
-            });
+            new(Native.OS.GetRelativePathToHome);
     }
 }

src/Native/OS.cs

@@ -229,6 +229,19 @@ public static string GetAbsPath(string root, string sub)
             return fullpath;
         }
 
+        public static string GetRelativePathToHome(string path)
+        {
+            if (OperatingSystem.IsWindows())
+                return path;
+
+            var home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
+            var prefixLen = home.EndsWith('/') ? home.Length - 1 : home.Length;
+            if (path.StartsWith(home, StringComparison.Ordinal))
+                return $"~{path.AsSpan(prefixLen)}";
+
+            return path;
+        }
+
         private static void UpdateGitVersion()
         {
             if (string.IsNullOrEmpty(_gitExecutable) || !File.Exists(_gitExecutable))