Add families list, member kind filter, sidebar counters, pagination

New Families list page (parents/children columns, edit goes to the
detail view). Members list gets a member/guardian/both filter so
guardians aren't just invisible. Sidebar now shows live counts for
pending parent claims and games missing a referee, always numeric.
Member, event, team, group, news and family lists are paginated with
a shared pager partial that preserves the query string.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

management/templates/management/event_list.html

@@ -80,6 +80,8 @@
         </div>
     </div>
 
+    {% include "management/_pagination.html" %}
+
     {% comment %} Dialogs live outside the table: <tbody> may only contain <tr> elements. {% endcomment %}
     {% for event in events %}
         {% if event.can_manage %}