fix(syncer): drop trailing newline from Success message to avoid blank line

The Success message used "Success: %s\n" while Timeout and Failed
used the trailing-newline-free form. Combined with msgTpl's own
"\n", the explicit \n in the format string produced an empty line
right after every successful repo. The output already includes a
visible separator from the Print template, so the extra blank line
was pure noise.

Drop the \n from the format string. Output now matches the Timeout
and Failed shapes: a single line ending in the template's trailing
newline.

Reported by GitHub Copilot on PR #26.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: takecy

syncer/syncer.go

@@ -194,7 +194,7 @@ func (s *Sync) execute(parent context.Context, repos []string, perRepoTimeout ti
 			switch {
 			case err == nil:
 				stats.addSuccess(r)
-				s.Writer.PrintMsg(fmt.Sprintf("Success: %s\n", r))
+				s.Writer.PrintMsg(fmt.Sprintf("Success: %s", r))
 			case errors.Is(ctx.Err(), context.DeadlineExceeded):
 				stats.addTimedOut(r)
 				s.Writer.PrintMsgErr(fmt.Sprintf("Timeout: %s", r))