Members page: show a live total member count

Count every membership account (free and paid together) on each page
load and show it under the headline; no per-tier numbers. Hidden when
there are no members.

Also correct the reference tiers.eom.json and service-groups.eom.json
to the real LDAP DNs (ou=Memberships; ou=<Service>,ou=Services), which
now match the ansible-role-www defaults.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

membership/templates/members.html

@@ -43,6 +43,7 @@
     <section class="member-hero">
         <p class="eyebrow">Music, films, projects &amp; shared worlds</p>
         <h1>Support the work.<br>Get closer to what’s next.</h1>
+        {% if member_count %}<p class="member-count"><strong>{{ member_count }}</strong> member{{ member_count|pluralize }} and counting</p>{% endif %}
         <p class="member-intro">Membership supports my music, films, writing, open-source projects, and game servers. Join the community for free, or choose a paid tier to support the work and receive the benefits listed below.</p>
         {% if account %}
         <div class="member-panel account-panel">