add support for version placeholder in download links

ModpackUpdater.Manager/Extensions.cs

@@ -40,4 +40,11 @@ public static class Extensions
             }
         }
     }
+
+    public static string GetSourceUrl(this InstallAction @this, Version version)
+    {
+        if (version is null)
+            return @this.SourceUrl;
+        return @this.SourceUrl.Replace("{version}", version.ToString(3));
+    }
 }

ModpackUpdater.Manager/ModpackFactory.cs

@@ -24,7 +24,7 @@ public class ModpackFactory
         modrinth.Dispose();
     }
 
-    public async Task<string> ResolveSourceUrl(InstallAction action)
+    public async Task<string> ResolveSourceUrl(InstallAction action, Version? targetVersion)
     {
         if (action.SourceType == SourceType.GitHub)
         {
@@ -53,7 +53,7 @@ public class ModpackFactory
                 return file.Url;
         }
 
-        return action.SourceUrl;
+        return action.GetSourceUrl(targetVersion);
     }
 
     public async Task<KeyValuePair<string, string>[]> FindUpdates(InstallAction action, string? gameVersion, ModLoader modLoader)

ModpackUpdater.Manager/ModpackInstaller.cs

@@ -150,8 +150,8 @@ public class ModpackInstaller(ModpackConfig updateConfig, ModpackInfo modpackInf
         {
             var destFilePath = Path.Combine(modpackInfo.LocaLPath, iaction.DestPath);
             var sourceUrl = updateConfig.PreferDirectLinks && !string.IsNullOrWhiteSpace(iaction.SourceUrl)
-               ? iaction.SourceUrl
-               : await factory.ResolveSourceUrl(iaction);
+                   ? iaction.GetSourceUrl(checkResult.LatestVersion)
+                   : await factory.ResolveSourceUrl(iaction, checkResult.LatestVersion);
 
             if (iaction is UpdateAction uaction)
             {