Add security to local directory setup

backend/main.go

@@ -39,7 +39,7 @@ func main() {
 	// Setup data directory
 	dataDir, err := setupDataDir()
 	if err != nil {
-		slog.Error("Cannot set data directory: %s; %w", os.Getenv("DATA_DIR"), err)
+		slog.Error("Cannot set data directory", "dir", os.Getenv("DATA_DIR"), "error", err)
 		os.Exit(1)
 	}