fix: address code review issues on PR #9

- gofmt main.go to fix tab indentation in main() body
- stats.go ComputeSummary: return nil when Answers and ByType are empty
- dns/types.go: remove duplicate ParseQueryType (dead code)
- formatter.go: log hook errors to stderr when Debug > 0; add Debug to Config
- text.go referralID: remove redundant depth==0 branch
- text.go writeServers: remove version lookup placeholder string

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: multica-agent <github@multica.ai>

internal/config/config.go

@@ -36,13 +36,13 @@ type Config struct {
 	Debug          int
 	Quiet          bool
 
-	ShowProgress        bool
-	ShowResolves        bool
-	ShowServers         bool
-	ShowVersions        bool
-	ShowAllStats        bool
-	ShowResults         bool
-	ShowSummaryResults  bool
+	ShowProgress       bool
+	ShowResolves       bool
+	ShowServers        bool
+	ShowVersions       bool
+	ShowAllStats       bool
+	ShowResults        bool
+	ShowSummaryResults bool
 }
 
 func ParseQueryType(s string) (uint16, error) {
@@ -235,4 +235,4 @@ func DefaultConfig() *Config {
 		ShowResults:        true,
 		ShowSummaryResults: true,
 	}
-}
+}