Checkpoint: management app redesign, onboarding/signup workflow, and events calendar backend

Large uncommitted body of work accumulated across sessions on this branch --
committing as a checkpoint so it's tracked and future worktree-isolated agents
see the real codebase instead of a stale ancestor commit. Covers the
management app's dedicated Tailwind theme and templates, the club onboarding
requirement/signup workflow (club/services/onboarding.py, requirement/status
models, sign-up dashboard), fee/status auto-activation decoupling, referee
management, and the new events calendar grid service layer.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ECGMEwrc2k4D8VQuwjstj9

controlpanel/urls.py

@@ -40,4 +40,6 @@ urlpatterns = [
     path("admins/add/", views.PlatformAdminAddView.as_view(), name="admin_add"),
     path("admins/<uuid:pk>/update/", views.PlatformAdminUpdateView.as_view(), name="admin_update"),
     path("admins/<uuid:pk>/revoke/", views.PlatformAdminRevokeView.as_view(), name="admin_revoke"),
+    # Jobs (Celery Beat's scheduled platform jobs -- monitoring only, see controlpanel/services/jobs.py)
+    path("jobs/", views.JobsView.as_view(), name="jobs"),
 ]