Add per-commit user

Change-Id: I099a03a97d9a700a1054e006468718d5daf6c824
diff --git a/server/agent/agent.go b/server/agent/agent.go
index e3aa766..d1c64a4 100644
--- a/server/agent/agent.go
+++ b/server/agent/agent.go
@@ -152,15 +152,6 @@
 		}
 	}
 
-	// Set git user configuration
-	userConfig := git.UserConfig{
-		Name:  a.Config.GitUsername,
-		Email: a.Config.GitEmail,
-	}
-	if err := a.gitInterface.SetUserConfig(ctx, userConfig); err != nil {
-		return fmt.Errorf("failed to set git user config: %w", err)
-	}
-
 	// Checkout to the specified branch
 	if a.Config.GitBranch != "" {
 		if err := a.gitInterface.Checkout(ctx, a.Config.GitBranch); err != nil {
@@ -319,7 +310,13 @@
 	}
 
 	commitMessage := fmt.Sprintf("feat: Complete task %s - %s", task.ID, task.Title)
-	if err := a.gitInterface.Commit(ctx, commitMessage, git.CommitOptions{}); err != nil {
+	if err := a.gitInterface.Commit(ctx, commitMessage, git.CommitOptions{
+		Author: &git.Author{
+			Name:  a.Config.GitUsername,
+			Email: a.Config.GitEmail,
+			Time:  time.Now(),
+		},
+	}); err != nil {
 		return fmt.Errorf("failed to commit solution: %w", err)
 	}