Add multiple network maps, graph UX improvements, and full backup import.

Support per-map contact membership with scoped graph views, relation editing on edges, layout caching, and automatic detection of full JSON backups so contacts and relations import together.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/contacts/urls.py

@@ -5,9 +5,25 @@ from . import views
 router = DefaultRouter()
 router.register('contacts', views.ContactViewSet)
 router.register('relations', views.RelationViewSet)
+router.register('network-maps', views.NetworkMapViewSet)
 
 urlpatterns = [
     path('', include(router.urls)),
+    path(
+        'network-maps/<int:map_pk>/memberships/',
+        views.NetworkMapMembershipViewSet.as_view({'get': 'list', 'post': 'create'}),
+        name='network-map-memberships-list',
+    ),
+    path(
+        'network-maps/<int:map_pk>/memberships/<int:pk>/',
+        views.NetworkMapMembershipViewSet.as_view({
+            'get': 'retrieve',
+            'patch': 'partial_update',
+            'put': 'update',
+            'delete': 'destroy',
+        }),
+        name='network-map-memberships-detail',
+    ),
     path('graph/', views.graph_data),
     path('network-map-graph/', views.network_map_graph),
     path('relation-types/', views.relation_types),