Enhancement: Empty config

When user starts kportal for the first time, and there is no config file,
kportal should create an empty config file with default values and empty
forwarding rules, so that user can easily edit the config file and add their
own rules.

internal/forward/manager.go

@@ -169,8 +169,10 @@ func (m *Manager) Start(cfg *config.Config) error {
 	// Get all forwards from config
 	forwards := cfg.GetAllForwards()
 
+	// Empty config is valid - user can add forwards later via TUI
 	if len(forwards) == 0 {
-		return fmt.Errorf("no forwards configured")
+		log.Printf("No forwards configured - use 'n' to add forwards")
+		return nil
 	}
 
 	// Check port availability before starting