Overhaul [1/n]

Signed-off-by: Sean Du <do4suki@gmail.com>

internal/handler/api/navigation/navigation.go

@@ -0,0 +1,15 @@
+package navigation
+
+import (
+	"fmt"
+)
+
+func NavigationApi(action string) (res any, err error) {
+	switch action {
+	case "specialCutin":
+		res, err = SpecialCutin()
+	default:
+		err = fmt.Errorf("unimplemented action: navigation: %s", action)
+	}
+	return res, err
+}