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/tiers.eom.json

@@ -5,7 +5,7 @@
     "price_id": "price_1Rgv4xC5KPXqTvVLfMd6z7wn",
     "price_label": "$4 USD / month",
     "usd_amount": "4.00",
-    "group_dn": "cn=Level 1,ou=Members,dc=eom,dc=dev",
+    "group_dn": "cn=Level 1,ou=Memberships,dc=eom,dc=dev",
       "description": "Go beyond the public feed.",
       "benefits": [
         "Exclusive Discourse and Matrix content, including work-in-progress updates",
@@ -19,7 +19,7 @@
     "price_id": "price_1Rgv5QC5KPXqTvVLv1PaHWb5",
     "price_label": "$8 USD / month",
     "usd_amount": "8.00",
-    "group_dn": "cn=Level 2,ou=Members,dc=eom,dc=dev",
+    "group_dn": "cn=Level 2,ou=Memberships,dc=eom,dc=dev",
       "description": "Try new work before release.",
       "benefits": [
         "Silver-tier giveaways",
@@ -32,7 +32,7 @@
     "price_id": "price_1Rgv5rC5KPXqTvVL8Ol8sMUf",
     "price_label": "$16 USD / month",
     "usd_amount": "16.00",
-    "group_dn": "cn=Level 3,ou=Members,dc=eom,dc=dev",
+    "group_dn": "cn=Level 3,ou=Memberships,dc=eom,dc=dev",
     "description": "Help shape the next experiment.",
     "benefits": [
       "Gold-tier giveaways",
@@ -46,7 +46,7 @@
     "price_id": "price_1Rgv6FC5KPXqTvVL39mAxYjm",
     "price_label": "$32 USD / month",
     "usd_amount": "32.00",
-    "group_dn": "cn=Level 4,ou=Members,dc=eom,dc=dev",
+    "group_dn": "cn=Level 4,ou=Memberships,dc=eom,dc=dev",
     "description": "Have a voice in the platform's direction.",
     "benefits": [
       "Platinum-tier giveaways",
@@ -59,7 +59,7 @@
     "price_id": "price_1Rgv6mC5KPXqTvVLkcmznWZa",
     "price_label": "$64 USD / month",
     "usd_amount": "64.00",
-    "group_dn": "cn=Level 5,ou=Members,dc=eom,dc=dev",
+    "group_dn": "cn=Level 5,ou=Memberships,dc=eom,dc=dev",
     "description": "Give the independent work its biggest boost.",
     "benefits": [
       "Diamond-tier giveaways",