feat(server): 询盘漏斗API——五级独立distinct会话计数/排除机器人

Co-Authored-By: Claude Code <noreply@anthropic.com>

server/config/urls.py

@@ -2,7 +2,7 @@ from django.urls import path
 from tracker.api.collect import CollectBatchView
 from tracker.api.auth import LoginView, RefreshView, MeView, UserCreateView
 from tracker.api.sites import SiteListView, SiteDetailView
-from tracker.api.dashboard import OverviewView
+from tracker.api.dashboard import FunnelSummaryView, OverviewView
 from tracker.api.visitors import (VisitorDetailView, VisitorListView,
                                   VisitorRawBatchesView, VisitorSessionView,
                                   VisitorTimelineView)
@@ -19,6 +19,7 @@ urlpatterns += [
     path("api/admin/sites", SiteListView.as_view()),
     path("api/admin/sites/<int:pk>", SiteDetailView.as_view()),
     path("api/admin/dashboard/overview", OverviewView.as_view()),
+    path("api/admin/funnel-summary", FunnelSummaryView.as_view()),
     path("api/admin/visitors", VisitorListView.as_view()),
     path("api/admin/visitors/<str:visitor_id>", VisitorDetailView.as_view()),
     path("api/admin/visitors/<str:visitor_id>/timeline", VisitorTimelineView.as_view()),