v0.0.16 | Floating IP attach/detach API 추가

- FloatingIpAttachView: LB의 vip_port_id를 조회하여 Floating IP 연결
- FloatingIpDetachView: Floating IP 연결 해제

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

nhn/urls.py

@@ -31,6 +31,8 @@ urlpatterns = [
 
     # ==================== Floating IP ====================
     path("floatingip/", views.FloatingIpListView.as_view(), name="floatingip-list"),
+    path("floatingip/<str:floating_ip_id>/attach/", views.FloatingIpAttachView.as_view(), name="floatingip-attach"),
+    path("floatingip/<str:floating_ip_id>/detach/", views.FloatingIpDetachView.as_view(), name="floatingip-detach"),
 
     # ==================== Security Group ====================
     path("securitygroup/", views.SecurityGroupListView.as_view(), name="securitygroup-list"),